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Singh A, Lal B, Kumar P, Parhar IS, Millar RP. Correction to: Role of Neurokinin B in gametogenesis and steroidogenesis of freshwater catfish, Clarias batrachus. Cell Tissue Res 2023; 393:595-596. [PMID: 37455268 DOI: 10.1007/s00441-023-03812-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Affiliation(s)
- Ankur Singh
- Fish Endocrinology Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, 221005, Varanasi, India
| | - Bechan Lal
- Fish Endocrinology Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, 221005, Varanasi, India.
| | - Pankaj Kumar
- Department of Zoology, Rajiv Gandhi University, Rono Hills, Doimukh, Itanagar, Arunachal Pradesh, India
| | - Ishwar S Parhar
- Brain Research Institute, School of Medicine and Health Sciences, Monash University, Sunway Campus, Malaysia
| | - Robert P Millar
- Centre for Neuroendocrinology, Department of Immunology, University of Pretoria, Pretoria and Department of Integrative Biomedical Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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Singh A, Lal B, Kumar P, Parhar IS, Millar RP. Role of Neurokinin B in gametogenesis and steroidogenesis of freshwater catfish, Clarias batrachus. Cell Tissue Res 2023; 393:377-391. [PMID: 37278825 DOI: 10.1007/s00441-023-03788-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/12/2023] [Indexed: 06/07/2023]
Abstract
Neurokinin B (NKB), a recently discovered neuropeptide, plays a crucial role in regulating the kiss-GnRH neurons in vertebrate's brain. NKB is also characterized in gonadal tissues; however, its role in gonads is poorly understood. Therefore, in the present study, the effects of NKB on gonadal steroidogenesis and gametogenesis through in vivo and in vitro approaches using NKB antagonist MRK-08 were evaluated. The results suggest that the NKB antagonist decreases the development of advanced ovarian follicles and germ cells in the testis. In addition, MRK-08 further reduces the production of 17β-estradiol in the ovary and testosterone in the testis under both in vivo and in vitro conditions in a dose-dependent manner. Furthermore, the in vitro MRK-08 treatment of gonadal explants attenuated the expression of steroidogenic marker proteins, i.e., StAR, 3β-HSD, and 17β-HSD dose-dependently. Moreover, the MAP kinase proteins, pERK1/2 & ERK1/2 and pAkt & Akt were also downregulated by MRK-08. Thus, the study suggests that NKB downregulates steroidogenesis by modulating the expressions of steroidogenic marker proteins involving ERK1/2 & pERK1/2 and Akt/pAkt signalling pathways. NKB also appears to regulate gametogenesis by regulating gonadal steroidogenesis in the catfish.
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Affiliation(s)
- Ankur Singh
- Fish Endocrinology Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, 221005, Varanasi, India
| | - Bechan Lal
- Fish Endocrinology Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, 221005, Varanasi, India.
| | - Pankaj Kumar
- Department of Zoology, Rajiv Gandhi University, Rono Hills, Doimukh, Itanagar, Arunachal Pradesh, India
| | - Ishwar S Parhar
- Brain Research Institute, School of Medicine and Health Sciences, Monash University, Sunway Campus, Malaysia
| | - Robert P Millar
- Centre for Neuroendocrinology, Department of Immunology, University of Pretoria, Pretoria and Department of Integrative Biomedical Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, South Africa
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Ludwig M, Newton C, Pieters A, Homer NZM, Feng Li X, O'Byrne KT, Millar RP. Provocative tests with Kisspeptin-10 and GnRH set the scene for determining social status and environmental impacts on reproductive capacity in male African lions (Panthera leo). Gen Comp Endocrinol 2022; 329:114127. [PMID: 36150474 DOI: 10.1016/j.ygcen.2022.114127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 08/25/2022] [Accepted: 09/16/2022] [Indexed: 11/24/2022]
Abstract
Understanding the hypothalamic factors regulating reproduction facilitates maximising the reproductive success of breeding programmes and in the management and conservation of threatened species, including African lions. To provide insight into the physiology and pathophysiology of the hypothalamic-pituitary-gonadal reproductive axis in lions, we studied the luteinising hormone (LH) and steroid hormone responses to gonadotropin-releasing hormone (GnRH) and its upstream regulator, kisspeptin. Six young (13.3 ± 1.7 months, 56.2 ± 4.3 kg) and four adult (40.2 ± 1.4 months, 174 ± 6 kg) male lions (Ukutula Conservation Centre, South Africa) were used in this study. Lions were immobilised with a combination of medetomidine and ketamine and an intravenous catheter was placed in a jugular, cephalic or medial saphenous vein for blood sampling at 10-min intervals for 220 min. The ten-amino acid kisspeptin which has full intrinsic activity (KP-10, 1 µg/kg) and GnRH (1 µg/kg) were administered intravenously to study their effects on LH and steroid hormone plasma concentrations, measured subsequently by ELISA and liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively. Basal LH levels were similarly low between the age groups, but testosterone and its precursor levels were higher in the adult animals. Adult lions showed a significant LH response to KP-10 (10-fold) and GnRH (11-fold) administration (p < 0.05 and P < 0.001, respectively) whereas in young lions LH increased significantly only in response to GnRH. In adults alone, testosterone and its precursors steadily increased in response to KP-10, with no significant further increase in response to GnRH. Plasma levels of glucocorticoids in response to KP-10 remained unchanged. We suggest that provocative testing of LH and steroid stimulation with kisspeptin provides a new and sensitive tool for determining reproductive status and possibly an index of exposure to stress, environmental insults such as disease, endocrine disruptors and nutritional status. 272 words.
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Affiliation(s)
- Mike Ludwig
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK; Department of Immunology, Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
| | - Claire Newton
- Department of Immunology, Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Ané Pieters
- Department of Immunology, Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Natalie Z M Homer
- BHF/University Centre for Cardiovascular Science and Mass Spectrometry Core, University of Edinburgh, UK
| | - Xiao Feng Li
- Department of Women and Children's Health, School of Life Course Sciences, King's College London, London, UK
| | - Kevin T O'Byrne
- Department of Women and Children's Health, School of Life Course Sciences, King's College London, London, UK
| | - Robert P Millar
- Department of Immunology, Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
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Zhang L, Padilla‐Flores T, Hernández VS, Zetter MA, Campos‐Lira E, Escobar LI, Millar RP, Eiden LE. Vasopressin acts as a synapse organizer in limbic regions by boosting PSD95 and GluA1 expression. J Neuroendocrinol 2022; 34:e13164. [PMID: 35666232 PMCID: PMC9787762 DOI: 10.1111/jne.13164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 05/01/2022] [Accepted: 05/10/2022] [Indexed: 12/31/2022]
Abstract
Hypothalamic arginine vasopressin (AVP)-containing magnocellular neurosecretory neurons (AVPMNN) emit collaterals to synaptically innervate limbic regions influencing learning, motivational behaviour, and fear responses. Here, we characterize the dynamics of expression changes of two key determinants for synaptic strength, the postsynaptic density (PSD) proteins AMPAR subunit GluA1 and PSD scaffolding protein 95 (PSD95), in response to in vivo manipulations of AVPMNN neuronal activation state, or exposure to exogenous AVP ex vivo. Both long-term water deprivation in vivo, which powerfully upregulates AVPMNN metabolic activity, and exogenous AVP application ex vivo, in brain slices, significantly increased GluA1 and PSD95 expression as measured by western blotting, in brain regions reportedly receiving direct ascending innervations from AVPMNN (i.e., ventral hippocampus, amygdala and lateral habenula). By contrast, the visual cortex, a region not observed to receive AVPMNN projections, showed no such changes. Ex vivo application of V1a and V1b antagonists to ventral hippocampal slices ablated the AVP stimulated increase in postsynaptic protein expression measured by western blotting. Using a modified expansion microscopy technique, we were able to quantitatively assess the significant augmentation of PSD95 and GLUA1 densities in subcellular compartments in locus coeruleus tyrosine hydroxylase immunopositive fibres, adjacent to AVP axon terminals. Our data strongly suggest that the AVPMNN ascending system plays a role in the regulation of the excitability of targeted neuronal circuits through upregulation of key postsynaptic density proteins corresponding to excitatory synapses.
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Affiliation(s)
- Limei Zhang
- Department of Physiology, School of MedicineNational Autonomous University of MexicoMexico CityMexico
| | - Teresa Padilla‐Flores
- Department of Physiology, School of MedicineNational Autonomous University of MexicoMexico CityMexico
| | - Vito S. Hernández
- Department of Physiology, School of MedicineNational Autonomous University of MexicoMexico CityMexico
| | - Mario A. Zetter
- Department of Physiology, School of MedicineNational Autonomous University of MexicoMexico CityMexico
| | - Elba Campos‐Lira
- Department of Physiology, School of MedicineNational Autonomous University of MexicoMexico CityMexico
| | - Laura I. Escobar
- Department of Physiology, School of MedicineNational Autonomous University of MexicoMexico CityMexico
| | - Robert P. Millar
- Department of Physiology, School of MedicineNational Autonomous University of MexicoMexico CityMexico
- Centre for Neuroendocrinology, Department of ImmunologyUniversity of PretoriaPretoriaSouth Africa
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular MedicineUniversity of Cape TownCape TownSouth Africa
| | - Lee E. Eiden
- Section on Molecular NeuroscienceNIMH‐IRP, NIHBethesdaMarylandUSA
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Affiliation(s)
- Robert P Millar
- Centre for Neuroendocrinology, Department of Immunology, University of Pretoria, Pretoria, South Africa
- Department of Integrative Biomedical Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Niki Karavitaki
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
- Department of Endocrinology, Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Darko Kastelan
- Department of Endocrinology, University Hospital Zagreb, Zagreb, Croatia
- School of Medicine, University of Zagreb, Zagreb, Croatia
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Anderson RA, Millar RP. The roles of kisspeptin and neurokinin B in GnRH pulse generation in humans, and their potential clinical application. J Neuroendocrinol 2022; 34:e13081. [PMID: 34962670 DOI: 10.1111/jne.13081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/22/2021] [Accepted: 12/14/2021] [Indexed: 12/22/2022]
Abstract
The delivery of gonadotropin-releasing hormone (GnRH) in a pulsatile mode to the gonadotropes has long been known to be essential for normal reproductive function. There have been numerous studies aimed at dissecting out the mechanisms underlying GnRH pulse generation. The discovery of kisspeptin as an upstream regulator of GnRH attracted the possibility that pulsatile kisspeptin governed the pulsatile secretion of GnRH. Subsequent studies have shown the importance of the neurokinin B (NKB) system in modulating kisspeptin secretion and this GnRH. A number of studies in laboratory rodents have supported this notion. By contrast, we present data from clinical studies in men and women, in a range of contexts, showing that continuous infusion of kisspeptin 10 at receptor-saturating levels gives rise to an increase in luteinizing hormone (LH) (GnRH) pulse frequency. This has been demonstrated in normal healthy and hypogonadal men, in normal women during the mid-cycle LH surge, in men and women with mutations in the genes encoding NKB or its receptor, neurokinin 3 receptor (NK3R), in women with polycystic ovary syndrome treated with NK3R antagonist, and in women treated with NK3R antagonist during the LH surge. These finds indicate that pulsatile secretion and action of kisspeptin on GnRH neurons is not required for the generation of LH (GnRH) pulses in humans. We also report that there is an absence of desensitization in humans exposed to continuous infusion of kisspeptin-10 at receptor-saturating concentrations over 22 h and briefly review GnRH, kisspeptin and NKB analogs and their clinical application.
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Affiliation(s)
- Richard A Anderson
- MRC Centre for Reproductive Health, Queens Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Robert P Millar
- Department of Immunology, Faculty of Health Sciences, Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa
- Department of Integrative Biomedical Sciences, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, Observatory, South Africa
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Anderson RC, Hanyroup S, Song YB, Mohamed-Moosa Z, van den Bout I, Schwulst AC, Kaiser UB, Millar RP, Newton CL. Functional Rescue of Inactivating Mutations of the Human Neurokinin 3 Receptor Using Pharmacological Chaperones. Int J Mol Sci 2022; 23:ijms23094587. [PMID: 35562976 PMCID: PMC9100388 DOI: 10.3390/ijms23094587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 12/04/2022] Open
Abstract
G protein-coupled receptors (GPCRs) facilitate the majority of signal transductions across cell membranes in humans, with numerous diseases attributed to inactivating GPCR mutations. Many of these mutations result in misfolding during nascent receptor synthesis in the endoplasmic reticulum (ER), resulting in intracellular retention and degradation. Pharmacological chaperones (PCs) are cell-permeant small molecules that can interact with misfolded receptors in the ER and stabilise/rescue their folding to promote ER exit and trafficking to the cell membrane. The neurokinin 3 receptor (NK3R) plays a pivotal role in the hypothalamic–pituitary–gonadal reproductive axis. We sought to determine whether NK3R missense mutations result in a loss of cell surface receptor expression and, if so, whether a cell-permeant small molecule NK3R antagonist could be repurposed as a PC to restore function to these mutants. Quantitation of cell surface expression levels of seven mutant NK3Rs identified in hypogonadal patients indicated that five had severely impaired cell surface expression. A small molecule NK3R antagonist, M8, increased cell surface expression in four of these five and resulted in post-translational receptor processing in a manner analogous to the wild type. Importantly, there was a significant improvement in receptor activation in response to neurokinin B (NKB) for all four receptors following their rescue with M8. This demonstrates that M8 may have potential for therapeutic development in the treatment of hypogonadal patients harbouring NK3R mutations. The repurposing of existing small molecule GPCR modulators as PCs represents a novel and therapeutically viable option for the treatment of disorders attributed to mutations in GPCRs that cause intracellular retention.
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Affiliation(s)
- Ross C. Anderson
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa; (S.H.); (Z.M.-M.); (I.v.d.B.); (A.C.S.); (R.P.M.); (C.L.N.)
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa
- Correspondence:
| | - Sharika Hanyroup
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa; (S.H.); (Z.M.-M.); (I.v.d.B.); (A.C.S.); (R.P.M.); (C.L.N.)
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa
| | - Yong Bhum Song
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.B.S.); (U.B.K.)
- Division of Research Center, Scripps Korea Antibody Institute, Chuncheon 24341, Korea
| | - Zulfiah Mohamed-Moosa
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa; (S.H.); (Z.M.-M.); (I.v.d.B.); (A.C.S.); (R.P.M.); (C.L.N.)
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa
- Department of Anatomy and Physiology, Faculty of Veterinary Sciences, University of Pretoria, Private Bag X04, Pretoria 0110, South Africa
| | - Iman van den Bout
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa; (S.H.); (Z.M.-M.); (I.v.d.B.); (A.C.S.); (R.P.M.); (C.L.N.)
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa
| | - Alexis C. Schwulst
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa; (S.H.); (Z.M.-M.); (I.v.d.B.); (A.C.S.); (R.P.M.); (C.L.N.)
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa
| | - Ursula B. Kaiser
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.B.S.); (U.B.K.)
| | - Robert P. Millar
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa; (S.H.); (Z.M.-M.); (I.v.d.B.); (A.C.S.); (R.P.M.); (C.L.N.)
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa
- Department of Integrative Biomedical Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Observatory 7925, South Africa
- Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9JZ, UK
- School of Medicine, Medical and Biological Sciences Building, University of St Andrews, St Andrews KY16 9TF, UK
| | - Claire L. Newton
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa; (S.H.); (Z.M.-M.); (I.v.d.B.); (A.C.S.); (R.P.M.); (C.L.N.)
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Pretoria 0031, South Africa
- Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9JZ, UK
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Burke CR, Roche JR, Millar RP, Clarke IJ. Onset of normal cycles in postpartum anovulatory dairy cattle treated with kisspeptin. Reproduction and Fertility 2022; 3:1-8. [PMID: 35118417 PMCID: PMC8789012 DOI: 10.1530/raf-21-0046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 11/08/2022] Open
Abstract
The efficacy of a long-acting synthetic derivative of kisspeptin (Kp) to initiate normal oestrous cycles was tested in 24 mixed-aged, Holstein-Friesian cows that were 18–25 days postpartum on the day of treatment (D0). Groups of eight cows received saline (Sal) vehicle by intramuscular injection at 8:00 and 16:00 h (Sal-Sal), Kp at 8:00 h and vehicle at 16:00 h (Kp-Sal) or Kp on both occasions (Kp-Kp). The Kp dose was 15 nmol per 60 kg body weight. The ovaries of the cows were examined daily by ultrasonography between D4 and D14. Blood samples were collected from a tail vessel at 0, 2, 4, 8, 10 and 12 h relative to the time of the first injection for luteinizing hormone (LH) and follicle-stimulating hormone assay. Additional samples were collected daily from D4 until D14 and D19, 22, 26 and 29 for progesterone assay. LH surge-like responses were observed in cows treated with Kp at 8:00 h. Ovulation was consistently induced by Kp within 48 h when a dominant ovarian follicle of at least 10 mm in diameter was observed (8/14) but in no cases (6/14) during a new wave of ovarian follicular development comprising follicles <10 mm in diameter. The subsequent ovulatory cycle was of normal length in most cases as compared with short 8– to 12-day cycles observed in spontaneously ovulating cows. We conclude that Kp treatment can induce ovulation in postpartum dairy cows, with ensuing oestrous cycles of normal length, if administered when a mature dominant follicle is present in the ovaries.
Lay summary
Cow fertility is important for efficient, profitable dairy farming. Cows that take too long after calving to become fertile are problematic. We tested a synthetically made, long-acting hormone called kisspeptin (Kp) to advance the time that cows become fertile after calving. Twenty-four dairy cows that had been calved for 3–4 weeks were used. One group of eight cows received an injection of Kp at the morning milking, another eight cows received Kp at both the morning and afternoon milking, while the last group of eight cows served as untreated controls. Kp treatment caused a desirable hormone response from the cows’ brain. Normal oestrous cycles resulted, but only when a mature follicle was present in the ovary. Further study is required to analyse whether the use of a long-acting Kp drug could be used as an effective treatment for stimulating dairy cows to become more fertile after calving.
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Affiliation(s)
| | | | - Robert P Millar
- 2Centre for Neuroendocrinology, Department of Immunology, University of Pretoria, Gezina, Pretoria, South Africa
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Hanyroup S, Anderson RC, Nataraja S, Yu HN, Millar RP, Newton CL. Rescue of Cell Surface Expression and Signaling of Mutant Follicle-Stimulating Hormone Receptors. Endocrinology 2021; 162:6311857. [PMID: 34192304 DOI: 10.1210/endocr/bqab134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Indexed: 11/19/2022]
Abstract
Mutations in G protein-coupled receptors (GPCRs) underlie numerous diseases. Many cause receptor misfolding and failure to reach the cell surface. Pharmacological chaperones are cell-permeant small molecules that engage nascent mutant GPCRs in the endoplasmic reticulum, stabilizing folding and "rescuing" cell surface expression. We previously demonstrated rescue of cell surface expression of luteinizing hormone receptor mutants by an allosteric agonist. Here we demonstrate that a similar approach can be employed to rescue mutant follicle-stimulating hormone receptors (FSHRs) with poor cell surface expression using a small-molecule FSHR agonist, CAN1404. Seventeen FSHR mutations described in patients with reproductive dysfunction were expressed in HEK 293T cells, and cell surface expression was determined by enzyme-linked immunosorbent assay of epitope-tagged FSHRs before/after treatment with CAN1404. Cell surface expression was severely reduced to ≤18% of wild-type (WT) for 11, modestly reduced to 66% to 84% of WT for 4, and not reduced for 2. Of the 11 with severely reduced cell surface expression, restoration to ≥57% of WT levels was achieved for 6 by treatment with 1 µM CAN1404 for 24 h, and a corresponding increase in FSH-induced signaling was observed for 4 of these, indicating restored functionality. Therefore, CAN1404 acts as a pharmacological chaperone and can rescue cell surface expression and function of certain mutant FSHRs with severely reduced cell surface expression. These findings aid in advancing the understanding of the effects of genetic mutations on GPCR function and provide a proof of therapeutic principle for FSHR pharmacological chaperones.
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Affiliation(s)
- Sharika Hanyroup
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Ross C Anderson
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | | | | | - Robert P Millar
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Integrative Biomedical Sciences, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, UK
- School of Medicine, Medical and Biological Sciences Building, University of St Andrews, St Andrews, UK
| | - Claire L Newton
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, UK
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Junco JA, Fuentes F, Millar RP. A dual kisspeptin-GnRH immunogen for reproductive immunosterilization. Vaccine 2021; 39:6437-6448. [PMID: 34489132 DOI: 10.1016/j.vaccine.2021.07.080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 07/07/2021] [Accepted: 07/28/2021] [Indexed: 02/03/2023]
Abstract
GnRH immunogens have been extensively employed in immunocontraception of animals. While they are effective, they are not 100% efficacious and of limited duration. GnRH secretion is dependent on upstream stimulation by kisspeptin. We therefore hypothesised that a dual immunogen combining GnRH and kisspeptin may be more efficacious through targeting two levels of the axis. We have previously shown GnRH immunogen elicits permanent sterilisation when sheep are vaccinated neonatally suggesting that the efficacy of GnRH immunisation may be dependent on the stage of reproductive development. We have now studied over 300 days the efficacy of immunisation with a dual immunogen comprising GnRH linked to kisspeptin via a hepatitis B T helper peptide sequence (GKT) administered to male and female rats prepubertally, pubertally and as adults. At all stages of development all immunised animals produced antibodies to GnRH, kisspeptin and GKT but differentially in titre with respect to sex and stage of development. In immunised adult, prepubertal and pubertal males testosterone and testes length was markedly reduced by 60 days and remained at low levels until day 150. Thereafter, testosterone recovered to pre immunisation levels and testes length increased to a maximum of about 40% of controls. 80% of males were infertile in three matings over 250 days. In prepubertal and pubertal female rats a single immunisation at day 0 reduced estradiol to low levels by day 60 which remained low until termination of the experiment on day 300. In matings of these females with fertile males on days 90, 120 and 250, 74% of prepubertal females were infertile and impressively, 100% (10/10) of pubertal females were infertile after a single immunisation on day 0. These findings set the scene for exploration of immunosterilisation of wild and domestic animals after a single immunisation.
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Affiliation(s)
- Jesus A Junco
- Prostate Cancer Department, Centre for Genetic Engineering and Biotechnology of Camaguey. Ave Finlay y Circunvalación Norte, CP 70100 Camaguey, Cuba
| | - Franklin Fuentes
- Prostate Cancer Department, Centre for Genetic Engineering and Biotechnology of Camaguey. Ave Finlay y Circunvalación Norte, CP 70100 Camaguey, Cuba
| | - Robert P Millar
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Gezina 0084, Pretoria, South Africa; Institute of Infectious Disease and Molecular Medicine, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Observatory 7925, Cape Town, South Africa.
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Robles JP, Zamora M, Siqueiros-Marquez L, Adan-Castro E, Ramirez-Hernandez G, Nuñez FF, Lopez-Casillas F, Millar RP, Bertsch T, Martínez de la Escalera G, Triebel J, Clapp C. The HGR motif is the antiangiogenic determinant of vasoinhibin: implications for a therapeutic orally active oligopeptide. Angiogenesis 2021; 25:57-70. [PMID: 34097181 PMCID: PMC8813873 DOI: 10.1007/s10456-021-09800-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/17/2021] [Indexed: 02/07/2023]
Abstract
The hormone prolactin acquires antiangiogenic and antivasopermeability properties after undergoing proteolytic cleavage to vasoinhibin, an endogenous prolactin fragment of 123 or more amino acids that inhibits the action of multiple proangiogenic factors. Preclinical and clinical evidence supports the therapeutic potential of vasoinhibin against angiogenesis-related diseases including diabetic retinopathy, peripartum cardiomyopathy, rheumatoid arthritis, and cancer. However, the use of vasoinhibin in the clinic has been limited by difficulties in its production. Here, we removed this barrier to using vasoinhibin as a therapeutic agent by showing that a short linear motif of just three residues (His46-Gly47-Arg48) (HGR) is the functional determinant of vasoinhibin. The HGR motif is conserved throughout evolution, its mutation led to vasoinhibin loss of function, and oligopeptides containing this sequence inhibited angiogenesis and vasopermeability with the same potency as whole vasoinhibin. Furthermore, the oral administration of an optimized cyclic retro-inverse vasoinhibin heptapeptide containing HGR inhibited melanoma tumor growth and vascularization in mice and exhibited equal or higher antiangiogenic potency than other antiangiogenic molecules currently used as anti-cancer drugs in the clinic. Finally, by unveiling the mechanism that obscures the HGR motif in prolactin, we anticipate the development of vasoinhibin-specific antibodies to solve the on-going challenge of measuring endogenous vasoinhibin levels for diagnostic and interventional purposes, the design of vasoinhibin antagonists for managing insufficient angiogenesis, and the identification of putative therapeutic proteins containing HGR.
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Affiliation(s)
- Juan Pablo Robles
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, México
| | - Magdalena Zamora
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, México
| | | | - Elva Adan-Castro
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, México
| | | | - Francisco Freinet Nuñez
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, México
| | - Fernando Lopez-Casillas
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Robert P Millar
- Institute of Infectious Disease and Molecular Medicine, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, 7925, South Africa
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Thomas Bertsch
- Institute for Clinical Chemistry, Laboratory Medicine and Transfusion Medicine, Nuremberg General Hospital & Paracelsus Medical University, Nuremberg, Germany
| | | | - Jakob Triebel
- Institute for Clinical Chemistry, Laboratory Medicine and Transfusion Medicine, Nuremberg General Hospital & Paracelsus Medical University, Nuremberg, Germany
| | - Carmen Clapp
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, México.
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Skorupskaite K, George JT, Veldhuis JD, Millar RP, Anderson RA. Kisspeptin and neurokinin B interactions in modulating gonadotropin secretion in women with polycystic ovary syndrome. Hum Reprod 2021; 35:1421-1431. [PMID: 32510130 PMCID: PMC7316500 DOI: 10.1093/humrep/deaa104] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 04/01/2020] [Indexed: 12/12/2022] Open
Abstract
STUDY QUESTION What is the role of the hypothalamic neuropeptide neurokinin B (NKB) and its interaction with kisspeptin on GnRH/LH secretion in women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER Administration of neurokinin 3 receptor antagonist (NK3Ra) for 7 days reduced LH and FSH secretion and LH pulse frequency in women with PCOS, whilst the stimulatory LH response to kisspeptin-10 was maintained. WHAT IS KNOWN ALREADY PCOS is characterized by abnormal GnRH/LH secretion. NKB and kisspeptin are master regulators of GnRH/LH secretion, but their role in PCOS is unclear. STUDY DESIGN, SIZE, DURATION The NK3Ra MLE4901, 40 mg orally twice a day, was administered to women with PCOS for 7 days (n = 8) (vs no treatment, n = 7). On the last day of NK3Ra administration or the equivalent day in those not treated, women were randomized to 7-h kisspeptin-10 (4 µg/kg/h i.v.) or vehicle infusion. This was repeated with the alternate infusion in a subsequent cycle. PARTICIPANTS/MATERIALS, SETTING, METHODS Subjects were women with PCOS, studied in a Clinical Research Facility. Reproductive hormones were measured before and after NK3Ra administration. On the last day of NK3Ra administration (or the equivalent cycle day in untreated women), all women attended for an 8-h frequent blood sampling to allow analysis of the pulsatile LH secretion. MAIN RESULTS AND THE ROLE OF CHANCE NK3Ra reduced LH secretion (4.0 ± 0.4 vs 6.5 ± 0.8 IU/l, P < 0.05) and pulse frequency (0.5 ± 0.1 vs 0.8 ± 0.1 pulses/h, P < 0.05); FSH secretion was also reduced (2.0 ± 0.3 vs 2.5 ± 0.4 IU/l, P < 0.05). Without NK3Ra pre-treatment, kisspeptin-10 increased LH secretion (5.2 ± 0.5 to 7.8 ± 1.0 IU/L, P < 0.05), with a positive relationship to oestradiol concentrations (r2 = 0.59, P < 0.05). After NK3Ra administration, the LH response to kisspeptin-10 was preserved (vehicle 3.5 ± 0.3 vs 9.0 ± 2.2 IU/l with kisspeptin-10, P < 0.05), but the positive correlation with oestradiol concentrations was abolished (r2 = 0.07, ns. after NK3Ra). FSH secretion was increased by kisspeptin-10 after NK3Ra treatment, but not without NK3Ra treatment. LIMITATIONS, REASONS FOR CAUTION The study did not explore the dose relationship of the effect of NK3R antagonism. The impact of obesity or other aspects of the variability of the PCOS phenotype was not studied due to the small number of subjects. WIDER IMPLICATIONS OF THE FINDINGS These data demonstrate the interactive regulation of GnRH/LH secretion by NKB and kisspeptin in PCOS, and that the NKB system mediates aspects of oestrogenic feedback. STUDY FUNDING/COMPETING INTEREST(S) Wellcome Trust through Scottish Translational Medicine and Therapeutics Initiative (102419/Z/13/A) and MRC grants (G0701682 to R.P.M. and R.A.A.) and MR/N022556/1 to the MRC Centre for Reproductive Health. This work was performed within the Edinburgh Clinical Research Facility. J.T.G. has undertaken consultancy work for AstraZeneca and Takeda Pharmaceuticals and is an employee of Boehringer Ingelheim. R.P.M. has consulted for Ogeda and was CEO of Peptocrine. R.A.A. has undertaken consultancy work for Merck, Ferring, NeRRe Therapeutics and Sojournix Inc. J.D.V. and K.S. have nothing to disclose. TRIAL REGISTRATION NUMBER N/A.
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Affiliation(s)
- Karolina Skorupskaite
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Jyothis T George
- Warwick Medical School, Coventry CV4 7AL, UK.,Boehringer Ingelheim, Bracknell RG12 8YS, UK
| | - Johannes D Veldhuis
- Endocrine Research Unit, Center for Translational Science Activities, Mayo Clinic, Rochester, MN 55905, USA
| | - Robert P Millar
- Centre for Neuroendocrinology and Mammal Research Institute, University of Pretoria, 0028 Pretoria, South Africa.,Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7925 Observatory, South Africa
| | - Richard A Anderson
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK
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Barraud S, Delemer B, Poirsier-Violle C, Bouligand J, Mérol JC, Grange F, Higel-Chaufour B, Decoudier B, Zalzali M, Dwyer AA, Acierno JS, Pitteloud N, Millar RP, Young J. Congenital Hypogonadotropic Hypogonadism with Anosmia and Gorlin Features Caused by a PTCH1 Mutation Reveals a New Candidate Gene for Kallmann Syndrome. Neuroendocrinology 2021; 111:99-114. [PMID: 32074614 DOI: 10.1159/000506640] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 02/18/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Two loci (CHD7 and SOX10) underlying Kallmann syndrome (KS) were discovered through clinical and genetic analysis of CHARGE and Waardenburg syndromes, conditions that include congenital anosmia caused by olfactory bulb (CA/OBs) defects and congenital hypogonadotropic hypogonadism (CHH). We hypothesized that other candidate genes for KS could be discovered by analyzing rare syndromes presenting with these signs. Study Design, Size, Duration: We first investigated a family with Gorlin-Goltz syndrome (GGS) in which affected members exhibited clinical signs suggesting KS. Participants/Materials, Methods: Proband and family members underwent detailed clinical assessment. The proband received detailed neuroendocrine evaluation. Genetic analyses included sequencing the PTCH1 gene at diagnosis, followed by exome analyses of causative or candidate KS/CHH genes, in order to exclude contribution to the phenotypes of additional mutations. Exome analyses in additional 124 patients with KS/CHH probands with no additional GGS signs. RESULTS The proband exhibited CA, absent OBs on magnetic resonance imaging, and had CHH with unilateral cryptorchidism, consistent with KS. Pulsatile Gonadotropin-releasing hormone (GnRH) therapy normalized serum gonadotropins and increased testosterone levels, supporting GnRH deficiency. Genetic studies revealed 3 affected family members harbor a novel mutation of PTCH1 (c.838G> T; p.Glu280*). This unreported nonsense deleterious mutation results in either a putative truncated Ptch1 protein or in an absence of translated Ptch1 protein related to nonsense mediated messenger RNA decay. This heterozygous mutation cosegregates in the pedigree with GGS and CA with OBs aplasia/hypoplasia and with CHH in the proband suggesting a genetic linkage and an autosomal dominant mode of inheritance. No pathogenic rare variants in other KS/CHH genes cosegregated with these phenotypes. In additional 124 KS/CHH patients, 3 additional heterozygous, rare missense variants were found and predicted in silico to be damaging: p.Ser1203Arg, p.Arg1192Ser, and p.Ile108Met. CONCLUSION This family suggests that the 2 main signs of KS can be included in GGS associated with PTCH1 mutations. Our data combined with mice models suggest that PTCH1 could be a novel candidate gene for KS/CHH and reinforce the role of the Hedgehog signaling pathway in pathophysiology of KS and GnRH neuron migration.
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Affiliation(s)
- Sara Barraud
- Department of Endocrinology, Reims University Hospital, Reims, France
- University of Reims Champagne-Ardenne, Reims, France
| | - Brigitte Delemer
- Department of Endocrinology, Reims University Hospital, Reims, France
- University of Reims Champagne-Ardenne, Reims, France
| | | | - Jérôme Bouligand
- Department of Molecular Genetics, Pharmacogenomics, and Hormonology, Assistance Publique-Hôpitaux de Paris, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
- University Paris-Saclay, Le Kremlin-Bicêtre, France
- INSERM U1185, Paris Saclay Medical School, Le Kremlin-Bicêtre, France
| | - Jean-Claude Mérol
- Department of Otolaryngology, Reims University Hospital, Reims, France
| | - Florent Grange
- Department of Dermatology, Reims University Hospital, Reims, France
| | | | | | - Mohamad Zalzali
- Department of Endocrinology, Reims University Hospital, Reims, France
| | - Andrew A Dwyer
- Boston College, William F. Connell School of Nursing, Chestnut Hill, Massachusetts, USA
| | - James S Acierno
- Service of Endocrinology, Diabetology and Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Nelly Pitteloud
- Service of Endocrinology, Diabetology and Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Robert P Millar
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Jacques Young
- University Paris-Saclay, Le Kremlin-Bicêtre, France,
- Department of Reproductive Endocrinology, Assistance Publique-Hôpitaux de Paris, Bicêtre Hospital, Le Kremlin-Bicêtre, France,
- INSERM U1185, Paris Saclay Medical School, Le Kremlin-Bicêtre, France,
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14
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Pivonello R, Auriemma RS, Pivonello C, Isidori AM, Corona G, Colao A, Millar RP. Sex Disparities in COVID-19 Severity and Outcome: Are Men Weaker or Women Stronger? Neuroendocrinology 2020; 111:1066-1085. [PMID: 33242856 PMCID: PMC7900484 DOI: 10.1159/000513346] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 11/25/2020] [Indexed: 12/11/2022]
Abstract
The coronavirus disease 2019 (COVID-19) outbreak, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global public health issue which has profound effects on most aspects of societal well-being, including physical and mental health. A plethora of studies globally have suggested the existence of a sex disparity in the severity and outcome of COVID-19 patients, mainly due to mechanisms of virus infection, immune response to the virus, development of systemic inflammation, and consequent systemic complications, particularly thromboembolism. Epidemiological data report a sex difference in the severity of COVID-19, with a more favorable course of the disease in women compared to men regardless of age, although the rate of SARS-CoV-2 infection seems to be similar in both sexes. Sex hormones, including androgens and estrogens, may not only impact virus entry and load, but also shape the clinical manifestations, complications, and ultimately the outcome of the disease. The current review comprehensively summarizes the current literature on sex disparities in susceptibility and outcome of COVID-19 as well as the literature underpinning the pathophysiological and molecular mechanisms, which may provide a rationale to a sex disparity. These mechanisms include sex hormone influence on factors that facilitate virus entry and priming, immune and inflammatory response, as well as coagulation and thrombosis diathesis. Based on present evidence, women appear to be relatively protected from COVID-19 because of a more effective immune response and a less pronounced systemic inflammation, with consequent moderate clinical manifestations of the disease, together with a lesser predisposition to thromboembolism. Conversely, men appear to be particularly susceptible to COVID-19 because of a less effective immune response with consequent severe clinical manifestations of the disease, together with a greater predisposition to thromboembolism. In the elderly, generally characterized by the phenomenon of inflammaging, sex disparities in overall mortality following SARS-CoV-2 infection are even more palpable as elderly men appear to be more prone to severe COVID-19 because of a greater predisposition to infections, a weaker immune defense, and an enhanced thrombotic state compared to women. The information revealed from the review highlights potential novel therapeutic approaches employing the administration of hormonal or antihormonal therapy in combination with antiviral drugs in COVID-19 patients.
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Affiliation(s)
- Rosario Pivonello
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Unità di Andrologia e Medicina della Riproduzione e della Sessualità Maschile e Femminile (FERTISEXCARES), Università Federico II di Napoli, Naples, Italy,
- UNESCO Chair for Health Education and Sustainable Development, Federico II University, Naples, Italy,
| | - Renata S Auriemma
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Università Federico II di Napoli, Naples, Italy
| | - Claudia Pivonello
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Università Federico II di Napoli, Naples, Italy
| | - Andrea M Isidori
- Department of Experimental Medicine, "Sapienza" University of Rome, Rome, Italy
| | - Giovanni Corona
- Endocrinology Unit, Medical Department, Maggiore-Bellaria Hospital, Bologna, Italy
| | - Annamaria Colao
- UNESCO Chair for Health Education and Sustainable Development, Federico II University, Naples, Italy
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Università Federico II di Napoli, Naples, Italy
| | - Robert P Millar
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Neurosciences Institute and Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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15
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Lübcker N, Whiteman JP, Newsome SD, Millar RP, de Bruyn PJN. Can the carbon and nitrogen isotope values of offspring be used as a proxy for their mother's diet? Using foetal physiology to interpret bulk tissue and amino acid δ 15N values. Conserv Physiol 2020; 8:coaa060. [PMID: 32765882 PMCID: PMC7397484 DOI: 10.1093/conphys/coaa060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 04/14/2020] [Accepted: 06/14/2020] [Indexed: 06/11/2023]
Abstract
The measurement of bulk tissue nitrogen (δ15N) and carbon isotope values (δ13C) chronologically along biologically inert tissues sampled from offspring can provide a longitudinal record of their mothers' foraging habits. This study tested the important assumption that mother-offspring stable isotope values are positively and linearly correlated. In addition, any change in the mother-offspring bulk tissues and individual amino acids that occurred during gestation was investigated. Whiskers sampled from southern elephant seal pups (Mirounga leonina) and temporally overlapping whiskers from their mothers were analyzed. This included n = 1895 chronologically subsampled whisker segments for bulk tissue δ15N and δ13C in total and n = 20 whisker segments for amino acid δ15N values, sampled from recently weaned pups (n = 17), juvenile southern elephant seals (SES) < 2 years old (n = 23) and adult female SES (n = 17), which included nine mother-offspring pairs. In contrast to previous studies, the mother-offspring pairs were not in isotopic equilibrium or linearly correlated during gestation: the Δ15N and Δ13C mother-offspring offsets increased by 0.8 and 1.2‰, respectively, during gestation. The foetal bulk δ15N values were 1.7 ± 0.5‰ (0.9-2.7‰) higher than mothers' δ15N values before birth, while the foetal δ13C increased by ~1.7‰ during gestation and were 1.0 ± 0.5‰ (0.0-1.9‰) higher than their mothers' δ13C at the end of pregnancy. The mother-offspring serine and glycine Δ15N differed by ~4.3‰, while the foetal alanine δ15N values were 1.4‰ lower than that of their mothers during the third trimester of pregnancy. The observed mother-offspring δ15N differences are likely explained by shuttling of glutamate-glutamine and glycine-serine amongst skeletal muscle, liver, placenta and foetal tissue. Foetal development relies primarily on remobilized endogenous maternal proteinaceous sources. Researchers should consider foetal physiology when using offspring bulk tissue isotope values as biomarkers for the mother's isotopic composition as part of monitoring programmes.
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Affiliation(s)
- Nico Lübcker
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa
| | - John P Whiteman
- Department of Biological Sciences, Old Dominion University, 5115 Hampton Boulevard, Norfolk, VA, 23529, USA
- Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Seth D Newsome
- Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Robert P Millar
- Centre for Neuroendocrinology and Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, 0001, South Africa
- Department of Integrative Biomedical Sciences, Neurosciences Institute and Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Anzio Road, Observatory 7925, South Africa
| | - P J Nico de Bruyn
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa
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16
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Lübcker N, Whiteman JP, Millar RP, de Bruyn PJN, Newsome SD. Fasting affects amino acid nitrogen isotope values: a new tool for identifying nitrogen balance of free-ranging mammals. Oecologia 2020; 193:53-65. [PMID: 32300864 DOI: 10.1007/s00442-020-04645-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 04/07/2020] [Indexed: 11/25/2022]
Abstract
Changes in the nutritional status of free-ranging animals have a strong influence on individual fitness, yet it remains challenging to monitor longitudinally. Nitrogen (δ15N) and carbon (δ13C) isotope values measured chronologically along the length of metabolically inert keratinous tissues can be used as a nutritional biomarker to retrospectively reconstruct the foraging ecology and eco-physiology of consumers. We quantitatively describe the physiological effects of fasting on amino acid metabolism using sequentially measured bulk tissue and amino acid δ15N values along the length of whiskers sampled from free-ranging juvenile, subadults, adult female, and male southern elephant seals (SES; Mirounga leonina) on Marion Island in the Southern Ocean. For both juveniles and adult females, whisker segments representing fasting had significantly higher bulk tissue δ15N values of 0.6 ± 0.5‰ and 1.3-1.8‰, respectively, in comparison to segments unaffected by fasting. We also found a large increase (2-6‰) in δ15N values for most glucogenic amino acids and a simultaneous depletion (2-3‰) of alanine in segments reflecting fasting, which enabled us to accurately predict (74%) the nutritional status of our model species. We hypothesize that the glucose-alanine cycle is the mechanism driving the observed depletion of alanine δ15N values during fasting. We demonstrated that keratinaceous tissues can be used as a longitudinal nutritional biomarker to detect changes in the nitrogen balance of an individual. Moreover, it is evident that physiological factors have an important influence on tissue δ15N values and can lead to erroneous bulk tissue or amino acid isotope-based reconstructions of foraging habits.
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Affiliation(s)
- Nico Lübcker
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa.
| | - John P Whiteman
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, 23529, USA.,Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Robert P Millar
- Centre for Neuroendocrinology and Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, 0001, South Africa
| | - P J Nico de Bruyn
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Seth D Newsome
- Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA
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17
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Lübcker N, Bloem LM, du Toit T, Swart P, de Bruyn PN, Swart AC, Millar RP. What’s in a whisker? High-throughput analysis of twenty-eight C19 and C21 steroids in mammalian whiskers by ultra-performance convergence chromatography-tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2020; 1141:122028. [DOI: 10.1016/j.jchromb.2020.122028] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/07/2020] [Accepted: 02/12/2020] [Indexed: 10/25/2022]
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18
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Van den Berghe F, Paris MCJ, Sarnyai Z, Briggs MB, Millar RP, Ganswindt A, Paris DBBP. Social rank does not affect sperm quality in male African wild dogs (Lycaon pictus). Reprod Fertil Dev 2020; 31:875-887. [PMID: 30694739 DOI: 10.1071/rd18205] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 12/03/2018] [Indexed: 11/23/2022] Open
Abstract
Sperm banking and AI could benefit endangered African wild dog conservation. However, it is unclear whether their dominance hierarchy causes a decrease in reproductive and sperm quality parameters in subordinate males that typically do not breed. In this study, we investigated the effect of social rank on male reproductive parameters, including faecal androgen and glucocorticoid metabolite concentrations, prostate and testes volume, preputial gland size, semen collection success and sperm quality. Samples were obtained from captive males (prebreeding season: n=12 from four packs; breeding season: n=24 from seven packs) that were classified as alpha (dominant), beta or gamma (subordinates) based on the frequency of dominant versus submissive behaviours. In the prebreeding season, semen was successfully collected from all alpha but only half the subordinate males, with urine contamination (associated with lower rank) significantly reducing total and progressive motility, sperm motility index, normal sperm morphology and acrosome integrity. The breeding season was associated with a significant increase in faecal androgens, prostate and testis volume, as well as progressive motility and the total number of spermatozoa ejaculated. However, with the exception of prostate volume (mean±s.e.m: 12.5±4.5, 7.1±1.0 and 7.3±1.0cm3 in alpha, beta and gamma males respectively; P=0.035), all other reproductive and sperm quality parameters did not differ between males of each social rank. In conclusion, reproductive suppression of subordinate males appears to be behaviourally mediated, because males of all social ranks produce semen of similar quality, making them suitable candidates for sperm banking, particularly during the breeding season when sperm quality improves.
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Affiliation(s)
- Femke Van den Berghe
- Gamete and Embryology (GAME) Laboratory, College of Public Health, Medical and Veterinary Sciences, James Cook University, James Cook Drive, Townsville, Qld 4811, Australia; and Institute for Breeding Rare and Endangered African Mammals (IBREAM), 9 Ainslie Place, Edinburgh, EH3 6AT, Scotland
| | - Monique C J Paris
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), 9 Ainslie Place, Edinburgh, EH3 6AT, Scotland; and Wageningen Livestock Research, De Elst 1, 6708 WD Wageningen, Netherlands
| | - Zoltan Sarnyai
- Laboratory of Psychiatric Neuroscience, Australian Institute of Tropical Health and Medicine (AITHM) and College of Public Health, Medical and Veterinary Sciences, James Cook University, Solander Drive, Townsville, Qld 4811, Australia
| | - Michael B Briggs
- African Predator Conservation Research Organisation (APCRO), 848 Rainbow Boulevard #A3, Las Vegas, NV 89107, USA
| | - Robert P Millar
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), 9 Ainslie Place, Edinburgh, EH3 6AT, Scotland; and Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria 0002, South Africa
| | - Andre Ganswindt
- Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, Hatfield 0028, South Africa; and Endocrine Research Laboratory, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
| | - Damien B B P Paris
- Gamete and Embryology (GAME) Laboratory, College of Public Health, Medical and Veterinary Sciences, James Cook University, James Cook Drive, Townsville, Qld 4811, Australia; and Centre for Tropical Environmental and Sustainability Science, James Cook University, James Cook Drive, Townsville, Qld 4811, Australia; and Corresponding author.
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Millar RP. Recollections on Jean E. Rivier: A Giant in Neuroendocrinology. Neuroendocrinology 2020; 110:443. [PMID: 32155644 DOI: 10.1159/000507085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 03/05/2020] [Indexed: 11/19/2022]
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Maione L, Fèvre A, Nettore IC, Manilall A, Francou B, Trabado S, Bouligand J, Guiochon-Mantel A, Delemer B, Flanagan CA, Macchia PE, Millar RP, Young J. Similarities and differences in the reproductive phenotypes of women with congenital hypogonadotrophic hypogonadism caused by GNRHR mutations and women with polycystic ovary syndrome. Hum Reprod 2019; 34:137-147. [PMID: 30476149 DOI: 10.1093/humrep/dey339] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 11/17/2018] [Indexed: 12/31/2022] Open
Abstract
STUDY QUESTION Does the phenotype of women with normosmic congenital hypogonadotrophic hypogonadism (nCHH) and pituitary resistance to GnRH caused by biallelic mutations in the GnRH receptor (GNRHR) (nCHH/bi-GNRHR) differ from that of women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER Women with nCHH/bi-GNRHR have variable pubertal development but nearly all have primary amenorrhea and an exaggerated LH response to GnRH stimulation, similar to that seen in women with PCOS. WHAT IS KNOWN ALREADY Women with nCHH/bi-GNRHR are very rare and their phenotype at diagnosis is not always adequately documented. The results of gonadotrophin stimulation by acute GnRH challenge test and ovarian features have not been directly compared between these patients and women with PCOS. STUDY DESIGN, SIZE, DURATION We describe the phenotypic spectrum at nCHH/bi-GNRHR diagnosis in a series of 12 women. Their reproductive characteristics and acute responses to GnRH were compared to those of 70 women with PCOS. PARTICIPANTS/MATERIALS, SETTING, METHODS Patients and controls (healthy female volunteers aged over 18 years) were enrolled in a single French referral centre. Evaluation included clinical and hormonal studies, pelvic ultrasonography and GnRH challenge test. We also functionally characterized two missense GNRHR mutations found in two new consanguineous families. MAIN RESULTS AND THE ROLE OF CHANCE Breast development was highly variable at nCHH/bi-GNRHR diagnosis, but only one patient had undeveloped breasts. Primary amenorrhea was present in all but two cases. In untreated nCHH/bi-GNRHR patients, uterine height (UH) correlated (P = 0.01) with the circulating estradiol level and was shorter than in 23 nulliparous post-pubertal age-matched controls (P < 0.0001) and than in 15 teenagers with PCOS under 20-years-old (P < 0.0001) in which PCOS was revealed by primary amenorrhea or primary-secondary amenorrhea. Unexpectedly, the stimulated LH peak response in nCHH/bi-GNRHR patients was variable, and often normal or exaggerated. Interestingly, the LH peak response was similar to that seen in the PCOS patients, but the latter women had significantly larger mean ovarian volume (P < 0.001) and uterine length (P < 0.001) and higher mean estradiol (P < 0.001), anti-Müllerian hormone (AMH) (P = 0.02) and inhibin-B (P < 0.001) levels. In the two new consaguineous families, the affected nCHH/bi-GNRHR women carried the T269M or Y290F GNRHR missense mutation in the homozygous state. In vitro analysis of GnRHR showed complete or partial loss-of-function of the T269M and Y290F mutants compared to their wildtype counterpart. LIMITATIONS, REASONS FOR CAUTION The number of nCHH/bi-GNRHR patients reported here is small. As this disorder is very rare, an international study would be necessary to recruit a larger cohort and consolidate the phenotypic spectrum observed here. WIDER IMPLICATIONS OF THE FINDINGS In teenagers and young women with primary amenorrhea, significant breast and uterine development does not rule out CHH caused by biallelic GNRHR mutations. In rare patients with PCOS presenting with primary amenorrhea and a mild phenotype, the similar exaggerated pituitary LH responses to GnRH in PCOS and nCHH/bi-GNRHR patients could lead to diagnostic errors. This challenge test should therefore not be recommended. As indicated by consensus and guidelines, careful analysis of clinical presentation and measurements of testosterone circulating levels remain the basis of PCOS diagnosis. Also, analysis of ovarian volume, UH and of inhibin-B, AMH, estradiol and androgen circulating levels could help to distinguish between mild PCOS and nCHH/bi-GNRHR. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by the French National Research Agency (ANR) grant ANR-09-GENO-017 KALGENOPATH, France; and by the Italian Ministry of Education, University and Research (MIUR) grant PRIN 2012227FLF_004, Italy. The authors declare no conflict of interest.
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Affiliation(s)
- Luigi Maione
- University of Paris-Sud and University Paris-Saclay, Le Kremlin-Bicêtre, France.,Assistance Publique-Hôpitaux de Paris, Hôpital Bicêtre, Department of Reproductive Endocrinology, Le Kremlin-Bicêtre, France.,Assistance Publique-Hôpitaux de Paris, Hôpital Bicêtre, Department of Molecular Genetics, Pharmacogenomics, and Hormonology, Le Kremlin-Bicêtre, France.,Department of Clinical Medicine and Surgery and Endocrinology, Federico II University, Naples, Italy
| | - Anne Fèvre
- Department of Endocrinology, Hôpital Robert-Debré, Reims, France
| | | | - Ashmeetha Manilall
- Faculty of Health Sciences, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
| | - Bruno Francou
- University of Paris-Sud and University Paris-Saclay, Le Kremlin-Bicêtre, France.,Assistance Publique-Hôpitaux de Paris, Hôpital Bicêtre, Department of Molecular Genetics, Pharmacogenomics, and Hormonology, Le Kremlin-Bicêtre, France
| | - Séverine Trabado
- University of Paris-Sud and University Paris-Saclay, Le Kremlin-Bicêtre, France.,Assistance Publique-Hôpitaux de Paris, Hôpital Bicêtre, Department of Molecular Genetics, Pharmacogenomics, and Hormonology, Le Kremlin-Bicêtre, France.,Institut National pour la Santé et la Recherche Médicale U1185, Paris-Sud Medical School, Le Kremlin-Bicêtre, France
| | - Jérôme Bouligand
- University of Paris-Sud and University Paris-Saclay, Le Kremlin-Bicêtre, France.,Assistance Publique-Hôpitaux de Paris, Hôpital Bicêtre, Department of Molecular Genetics, Pharmacogenomics, and Hormonology, Le Kremlin-Bicêtre, France.,Institut National pour la Santé et la Recherche Médicale U1185, Paris-Sud Medical School, Le Kremlin-Bicêtre, France
| | - Anne Guiochon-Mantel
- University of Paris-Sud and University Paris-Saclay, Le Kremlin-Bicêtre, France.,Assistance Publique-Hôpitaux de Paris, Hôpital Bicêtre, Department of Molecular Genetics, Pharmacogenomics, and Hormonology, Le Kremlin-Bicêtre, France.,Institut National pour la Santé et la Recherche Médicale U1185, Paris-Sud Medical School, Le Kremlin-Bicêtre, France
| | - Brigitte Delemer
- Department of Endocrinology, Hôpital Robert-Debré, Reims, France
| | - Colleen A Flanagan
- Faculty of Health Sciences, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
| | - Paolo Emidio Macchia
- Department of Clinical Medicine and Surgery and Endocrinology, Federico II University, Naples, Italy
| | - Robert P Millar
- Departments of Immunology and Physiology, Faculty of Health Sciences, Centre for Neuroendocrinology, University of Pretoria, Pretoria 0084, South Africa and Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Observatory, South Africa
| | - Jacques Young
- University of Paris-Sud and University Paris-Saclay, Le Kremlin-Bicêtre, France.,Assistance Publique-Hôpitaux de Paris, Hôpital Bicêtre, Department of Reproductive Endocrinology, Le Kremlin-Bicêtre, France.,Institut National pour la Santé et la Recherche Médicale U1185, Paris-Sud Medical School, Le Kremlin-Bicêtre, France
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Van den Berghe F, Paris MCJ, Sarnyai Z, Vlamings B, Millar RP, Ganswindt A, Cozzi A, Pageat P, Paris DBBP. Dog appeasing pheromone prevents the androgen surge and may reduce contact dominance and active submission after stressful interventions in African wild dogs (Lycaon pictus). PLoS One 2019; 14:e0212551. [PMID: 30917139 PMCID: PMC6436694 DOI: 10.1371/journal.pone.0212551] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 02/05/2019] [Indexed: 11/20/2022] Open
Abstract
The endangered African wild dog (AWD; Lycaon pictus) is a highly social canid living in packs with a separate male and female hierarchy. Immobilisation, handling and translocations are acute stressors for AWDs, however such interventions are often needed for species management. In addition, new pack formation or temporary pack separation can lead to an increase in intra-pack aggression. The goal of this double-blinded placebo-controlled study conducted in captive zoo populations was to evaluate whether dog appeasing pheromone (DAP) reduces behavioural stress and faecal glucocorticoid metabolite levels (fGCM) normally associated with pack separation, immobilisation and reintroduction (SIR), and to assess whether this reduces aggressive behaviours and faecal androgen metabolite levels (fAM). Four packs (n = 11 males) were treated with DAP and 4 packs (n = 12 males) were treated with a placebo solution, applied at the end of anaesthesia. Behavioural interactions as well as fGCM and fAM were determined from 3 days before until 4-6 days after SIR. No effect of DAP on fGCM was observed, however, fAM increased after SIR in placebo but not DAP treated animals. Moreover, on the day of reintroduction, DAP treated packs tended to have lower rates of contact-dominance and active-submission behaviour, but higher rates of non-contact dominance behaviour. As these effects could decrease the risk of agonistic interactions, DAP may be a useful tool to help manage new pack formations and temporary pack separation.
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Affiliation(s)
- Femke Van den Berghe
- Gamete and Embryology (GAME) Laboratory, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
| | - Monique C. J. Paris
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
- Wageningen Livestock Research, Wageningen, The Netherlands
| | - Zoltan Sarnyai
- Laboratory of Psychiatric Neuroscience, Australian Institute of Tropical Health and Medicine (AITHM) and College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
| | - Bart Vlamings
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
| | - Robert P. Millar
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Andre Ganswindt
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
- Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
- Endocrine Research Laboratory, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Alessandro Cozzi
- Institut de Recherche en Sémiochimie et Ethologie Appliquée, Apt, France
| | - Patrick Pageat
- Institut de Recherche en Sémiochimie et Ethologie Appliquée, Apt, France
| | - Damien B. B. P. Paris
- Gamete and Embryology (GAME) Laboratory, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
- Institute for Breeding Rare and Endangered African Mammals (IBREAM), Edinburgh, Scotland
- Centre for Tropical Environmental & Sustainability Science, James Cook University, Townsville, QLD, Australia
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22
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Manilall A, Stander BA, Madziva MT, Millar RP, Flanagan CA. Glu 2.53(90) of the GnRH receptor is part of the conserved G protein-coupled receptor structure and does not form a salt-bridge with Lys 3.32(121). Mol Cell Endocrinol 2019; 481:53-61. [PMID: 30476558 DOI: 10.1016/j.mce.2018.11.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 11/19/2018] [Accepted: 11/22/2018] [Indexed: 01/22/2023]
Abstract
GnRH receptor mutations, Glu2.53(90)Lys and Glu2.53(90)Asp, cause congenital hypogonadotropic hypogonadism. The Glu2.53(90) side-chain has been proposed to form an intramolecular salt-bridge with Lys3.32(121), but conserved intramolecular interaction networks in G protein-coupled receptor crystal structures predict that it interacts with Ser3.35(124) and Trp6.48(280). We investigated interhelical interactions of Glu2.53(90) that stabilise GnRH receptor folding using functional analyses and computational modelling of mutant receptors. The Glu2.53(90)Asp mutant was non-functional, but mutants with hydrophobic amino acids or Arg substituted for Glu2.53(90) were functional, excluding a salt-bridge interaction. The Glu2.53(90)Arg and Trp6.48(280)Arg mutants had decreased affinity for GnRH. Models showed that congenital Glu2.53(90)Lys and Glu2.53(90)Asp mutations disrupt interactions with Ser3.35(124) and Trp6.48(280) respectively, whereas the Glu2.53(90)Arg and Trp6.48(280)Arg mutations preserve intramolecular contacts, but increase distance between the transmembrane helices. Our results show that disruption of interhelical contacts that are conserved in G protein-coupled receptors accounts for the effects of some disease-associated GnRH receptor mutations.
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Affiliation(s)
- Ashmeetha Manilall
- School of Physiology, University of the Witwatersrand Faculty of Health Sciences, Parktown, Johannesburg, South Africa
| | - B Andre Stander
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Michael T Madziva
- School of Physiology, University of the Witwatersrand Faculty of Health Sciences, Parktown, Johannesburg, South Africa
| | - Robert P Millar
- Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa
| | - Colleen A Flanagan
- School of Physiology, University of the Witwatersrand Faculty of Health Sciences, Parktown, Johannesburg, South Africa.
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23
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Prevot V, Millar RP. New Developments in Reproductive and Stress Neuroendocrinology. Neuroendocrinology 2019; 109:191-192. [PMID: 31365917 DOI: 10.1159/000502420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 07/30/2019] [Indexed: 11/19/2022]
Affiliation(s)
- Vincent Prevot
- Laboratory of Development and Plasticity of the Neuroendocrine Brain, INSERM, University of Lille, UMR-S 1172, Lille, France,
| | - Robert P Millar
- Centre for Neuroendocrinology, Department of Immunology, University of Pretoria, Pretoria, South Africa
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24
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Aggarwal S, Tang C, Sing K, Kim HW, Millar RP, Tello JA. Medial Amygdala Kiss1 Neurons Mediate Female Pheromone Stimulation of Luteinizing Hormone in Male Mice. Neuroendocrinology 2019; 108:172-189. [PMID: 30537700 PMCID: PMC6518874 DOI: 10.1159/000496106] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 12/07/2018] [Indexed: 01/02/2023]
Abstract
BACKGROUND/AIMS The medial amygdala (MeA) responds to olfactory stimuli and alters reproductive physiology. However, the neuronal circuit that relays signals from the MeA to the reproductive axis remains poorly defined. This study aimed to test whether MeA kisspeptin (MeAKiss) neurons in male mice are sensitive to sexually relevant olfactory stimuli and transmit signals to alter reproductive physiology. We also investigated whether MeAKiss neurons have the capacity to elaborate glutamate and GABA neurotransmitters and potentially contribute to reproductive axis regulation. METHODS Using female urine as a pheromone stimulus, MeAKiss neuronal activity was analysed and serum luteinizing hormone (LH) was measured in male mice. Next, using a chemogenetic approach, MeAKiss neurons were bi-directionally modulated to measure the effect on serum LH and evaluate the activation of the preoptic area. Lastly, using in situ hybridization, we identified the proportion of MeAKiss neurons that express markers for GABAergic (Vgat) and glutamatergic (Vglut2) neurotransmission. RESULTS Male mice exposed to female urine showed a two-fold increase in the number of c-Fos-positive MeAKiss neurons concomitant with raised LH. Chemogenetic activation of MeAKiss neurons significantly increased LH in the absence of urine exposure, whereas inhibition of MeAKiss neurons did not alter LH. In situ hybridization revealed that MeAKiss neurons are a mixed neuronal population in which 71% express Vgat mRNA, 29% express Vglut2 mRNA, and 6% express both. CONCLUSIONS Our results uncover, for the first time, that MeAKiss neurons process sexually relevant olfactory signals to influence reproductive hormone levels in male mice, likely through a complex interplay of neuropeptide and neurotransmitter signalling.
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Affiliation(s)
- Sanya Aggarwal
- School of Medicine, University of St. Andrews, St. Andrews, United Kingdom
| | - Celion Tang
- School of Medicine, University of St. Andrews, St. Andrews, United Kingdom
| | - Kristen Sing
- School of Medicine, University of St. Andrews, St. Andrews, United Kingdom
| | - Hyun Wook Kim
- School of Medicine, University of St. Andrews, St. Andrews, United Kingdom
| | - Robert P Millar
- Centre for Neuroendocrinology, Department of Physiology and Department of Immunology, University of Pretoria, Pretoria, South Africa
- Department of Integrative Biomedical Sciences, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Javier A Tello
- School of Medicine, University of St. Andrews, St. Andrews, United Kingdom,
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25
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Anderson RC, Newton CL, Anderson RA, Millar RP. Gonadotropins and Their Analogs: Current and Potential Clinical Applications. Endocr Rev 2018; 39:911-937. [PMID: 29982442 DOI: 10.1210/er.2018-00052] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 06/25/2018] [Indexed: 12/15/2022]
Abstract
The gonadotropin receptors LH receptor and FSH receptor play a central role in governing reproductive competency/fertility. Gonadotropin hormone analogs have been used clinically for decades in assisted reproductive therapies and in the treatment of various infertility disorders. Though these treatments are effective, the clinical protocols demand multiple injections, and the hormone preparations can lack uniformity and stability. The past two decades have seen a drive to develop chimeric and modified peptide analogs with more desirable pharmacokinetic profiles, with some displaying clinical efficacy, such as corifollitropin alfa, which is now in clinical use. More recently, low-molecular-weight, orally active molecules with activity at gonadotropin receptors have been developed. Some have excellent characteristics in animals and in human studies but have not reached the market-largely as a result of acquisitions by large pharma. Nonetheless, such molecules have the potential to mitigate risks currently associated with gonadotropin-based fertility treatments, such as ovarian hyperstimulation syndrome and the demands of injection-based therapies. There is also scope for novel use beyond the current remit of gonadotropin analogs in fertility treatments, including application as novel contraceptives; in the treatment of polycystic ovary syndrome; in the restoration of function to inactivating mutations of gonadotropin receptors; in the treatment of ovarian and prostate cancers; and in the prevention of bone loss and weight gain in postmenopausal women. Here we review the properties and clinical application of current gonadotropin preparations and their analogs, as well as the development of novel orally active, small-molecule nonpeptide analogs.
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Affiliation(s)
- Ross C Anderson
- Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa.,Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Claire L Newton
- Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa.,Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Richard A Anderson
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Robert P Millar
- Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa.,Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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Abstract
Dysregulation at any level of the hypothalamic-pituitary-gonadal (HPG) axis results in, or aggravates, a number of hormone-dependent diseases such as delayed or precocious puberty, infertility, prostatic and ovarian cancer, benign prostatic hyperplasia, polycystic ovarian syndrome, endometriosis, uterine fibroids, lean body mass, as well as metabolism and cognitive impairment. As gonadotropin-releasing-hormone (GnRH) is an essential regulator of the HPG axis, agonist and antagonist analogs are efficacious in the treatment of these conditions. GnRH analogs also play an important role in assisted reproductive therapies. This review highlights the current and future therapeutic potential of GnRH analogs and upstream regulators of GnRH secretion.
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Affiliation(s)
- Claire L Newton
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Centre for Integrative Physiology, Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, UK
| | - Carmen Riekert
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Robert P Millar
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa - .,Centre for Integrative Physiology, Deanery of Biomedical Sciences, University of Edinburgh, Edinburgh, UK.,Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.,Department of Integrative Biomedical Sciences, and Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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27
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Smith JT, Roseweir A, Millar M, Clarke IJ, Millar RP. Stimulation of growth hormone by kisspeptin antagonists in ewes. J Endocrinol 2018; 237:165-173. [PMID: 29549187 DOI: 10.1530/joe-18-0074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 03/15/2018] [Indexed: 11/08/2022]
Abstract
Kisspeptin signalling is indispensable for fertility, stimulating gonadotropin-releasing hormone (GnRH) secretion and mediating gonadal steroid feedback on GnRH neurons. Moreover, kisspeptin neurons have been implicated in other non-reproductive neuroendocrine roles. Kisspeptin appears to also regulate growth hormone secretion but much of the data appear contradictory. We sought to clarify a potential role of kisspeptin in growth hormone (GH) regulation by examining the effect of kisspeptin antagonists on GH secretion in ewes under various physiological conditions. Our data show clear and robust increases in GH secretion following lateral ventricle or third ventricle infusion of kisspeptin antagonists p-234 and p-271 in either ovariectomized or anestrous ewes. Central infusion of kisspeptin-10 had no effect on GH secretion. To determine the level at which kisspeptin may influence GH secretion, we examined expression of the cognate kisspeptin receptor, GPR54, in pituitary cells and showed by immunocytochemistry that the majority of somatotropes express GPR54 while expression was largely negative in other pituitary cells. Overall, we have demonstrated that blocking kisspeptin signalling by antagonists stimulates GH secretion in ewes and that this is likely mediated by inhibiting endogenous kisspeptin activation of GPR54 expressed on somatotropes. The findings suggest that endogenous kisspeptin inhibits GH secretion through GPR54 expressed on somatotropes.
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Affiliation(s)
- J T Smith
- School of Human SciencesThe University of Western Australia, Perth, Western Australia, Australia
| | - A Roseweir
- Academic Unit of SurgerySchool of Medicine, University of Glasgow, Royal Infirmary, Glasgow, UK
- Unit of Experimental TherapeuticsInstitute of Cancer Sciences, University of Glasgow Glasgow, UK
| | - M Millar
- Queen's Medical Research InstituteUniversity of Edinburgh, Edinburgh, UK
| | - I J Clarke
- Department of PhysiologyMonash University, Clayton, Victoria, Australia
| | - R P Millar
- Centre for NeuroendocrinologyDepartment of Immunology and Physiology, University of Pretoria, Pretoria, South Africa
- Institute for Infectious Diseases and Molecular MedicineUniversity of Cape Town, Cape Town, South Africa
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28
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Bornman M, Delport R, Farías P, Aneck-Hahn N, Patrick S, Millar RP, de Jager C. Alterations in male reproductive hormones in relation to environmental DDT exposure. Environ Int 2018; 113:281-289. [PMID: 29373146 DOI: 10.1016/j.envint.2017.12.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 12/30/2017] [Accepted: 12/31/2017] [Indexed: 06/07/2023]
Abstract
DDT [1, 1, 1-trichloro-2,2-bis (p-chlorophenyl)-ethane] compounds are used for indoor residual spraying (IRS) to control malaria mosquitoes. DDT is an endocrine disruptor chemical in experimental conditions, but little is known of adverse effects related to living conditions with continual uptake across a time span by all possible means of exposure. Based on estrogenic and/or anti-androgenic effects found in animal studies, we hypothesized that chronic DDT/DDE exposures in men may be associated with changes in male reproductive hormones. We tested this hypothesis by compared the magnitude and direction of associations between DDT and DDE (1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene) concentrations and male reproductive hormones in samples collected from IRS and non-IRS areas. We sampled a cross-section of 535 men (aged 18-40 years). Men living in IRS villages had significantly higher DDT and DDE concentrations compared with men from non-IRS villages. Men with DDT or DDE uptake (as reflected in detectable plasma concentrations) had significantly higher total-, free and bio-available testosterone (T), and lower follicle stimulating hormone (FSH) concentrations; lower luteinizing hormone (LH) concentrations were only evident with DDT uptake. To establish a dose-dependent effect, four sub-categories were defined. Men with the highest DDT (74-519 μg/g) and DDE (173-997 μg/g) concentrations had significantly higher total-, free and bio-available T, and lower FSH concentrations compared with subjects with non-detectable isomer concentrations. Estradiol concentrations were significantly higher in men with DDT and DDE concentrations in both the third (DDE: 27-172 μg/g; DDT: 5-73 μg/g) and fourth (DDE: 173-997 μg/g; DDT: 74-519 μg/g) categories. Men from IRS villages were significantly more likely to have higher total and bioavailable T as well as higher estradiol concentrations OR = 2.5 (95% CI 1.2, 3.2); OR 2.5 (95% CI 1.6, 4.0) and OR = 2.3 (95% CI 1.3, 4.1) compared to men from non-IRS villages, after controlling for age, BMI, personal use of pesticides, and smoking. Men living in IRS villages with life-long exposure (17.6 (±6) years) at the current residence with multiple exposure modalities incurred the highest degree of physiological imbalance over and above circulating isomer concentrations. Further studies are needed to elucidate the health implications of these findings.
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Affiliation(s)
- Maria Bornman
- School of Health Systems and Public Health (SHSPH), University of Pretoria, Institute for Sustainable Malaria Control (UP ISMC) and MRC Collaborating Centre for Malaria Research, University of Pretoria, Pretoria, South Africa; Hormone Dependent Cancer Consortium, University of Pretoria, Pretoria, South Africa.
| | - Rhena Delport
- Department of Chemical Pathology and UP ISMC, University of Pretoria, Pretoria, South Africa
| | | | - Natalie Aneck-Hahn
- Department of Urology, SHSPH and UP ISMC, University of Pretoria, Pretoria, South Africa
| | - Sean Patrick
- School of Health Systems and Public Health (SHSPH), University of Pretoria, Institute for Sustainable Malaria Control (UP ISMC) and MRC Collaborating Centre for Malaria Research, University of Pretoria, Pretoria, South Africa
| | - Robert P Millar
- Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa; Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa; Centre for Integrative Physiology, University of Edinburgh, Edinburgh, Scotland, United Kingdom; Hormone Dependent Cancer Consortium, University of Pretoria, Pretoria, South Africa
| | - Christiaan de Jager
- School of Health Systems and Public Health (SHSPH), University of Pretoria, Institute for Sustainable Malaria Control (UP ISMC) and MRC Collaborating Centre for Malaria Research, University of Pretoria, Pretoria, South Africa
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Clarke IJ, Li Q, Henry BA, Millar RP. Continuous Kisspeptin Restores Luteinizing Hormone Pulsatility Following Cessation by a Neurokinin B Antagonist in Female Sheep. Endocrinology 2018; 159:639-646. [PMID: 29126131 DOI: 10.1210/en.2017-00737] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 10/27/2017] [Indexed: 11/19/2022]
Abstract
Pulsatile secretion of the gonadotropin-releasing hormone (GnRH) drives pulsatile secretion of the luteinizing hormone (LH), with evidence that this depends on kisspeptin (Kiss) input to GnRH neurons. Kiss administration causes acute GnRH/LH secretion, and electrophysiological data suggest that Kiss neurons may act in a phasic manner to drive GnRH secretion, but there is not definitive evidence for this. The product of the Kiss-1 gene is proteolytically cleaved to smaller products, and the 10 amino acid C-terminal product (Kiss-10) displays full bioactivity. We have shown previously that continuous delivery of Kiss-10 to anestrous ewes can cause a surge in GnRH secretion and ovulation and increases LH pulse frequency in humans. Here, we tested the hypothesis that continuous Kiss-10 delivery can support pulsatile GnRH/LH secretion in the sheep. Neurokinin B (NKB) provides positive drive to Kiss neurons, so we therefore infused an NKB antagonist (ANT-08) intracerebroventricularly to induce cessation of pulsatile GnRH/LH secretion, with or without concomitant continuous Kiss-10 infusion. ANT-08 suppressed GnRH/LH pulsatility, which was immediately restored with continuous Kiss-10 infusion. These data support the notion that Kiss-10 action is downstream of NKB signaling and that continuous Kiss-10 stimulation of GnRH neurons is sufficient to support a pulsatile pattern of GnRH/LH secretion. This offers further support to the theory that GnRH pulse generation is intrinsic to GnRH neurons and that pulsatile GnRH release can be affected with continuous stimulation by Kiss-10.
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Affiliation(s)
- Iain J Clarke
- Neuroscience Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
- Department of Physiology, Monash University, Melbourne, Victoria, Australia
| | - Qun Li
- Neuroscience Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
- Department of Physiology, Monash University, Melbourne, Victoria, Australia
| | - Belinda A Henry
- Department of Physiology, Monash University, Melbourne, Victoria, Australia
- Metabolic Disease and Obesity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Robert P Millar
- Division of Medical Biochemistry, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Department of Physiology, Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa
- Department of Immunology, Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa
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Skorupskaite K, George JT, Veldhuis JD, Millar RP, Anderson RA. Neurokinin 3 Receptor Antagonism Reveals Roles for Neurokinin B in the Regulation of Gonadotropin Secretion and Hot Flashes in Postmenopausal Women. Neuroendocrinology 2018; 106:148-157. [PMID: 28380486 DOI: 10.1159/000473893] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 04/01/2017] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Neurokinin B (NKB) and kisspeptin are obligate for normal gonadotropin secretion, and links between gonadotropin-releasing hormone (GnRH) pulsatility and vasomotor symptoms have been proposed. Using a selective NKB receptor (NK3R) antagonist, the role of NKB in the hypergonadotropic state in menopausal women was explored. METHODS Eleven postmenopausal women were administered the NK3R antagonist MLE4901 at 40 mg twice daily orally for 7 days. Ten-minute blood sampling for 8 h was performed before and on the last day of NK3R antagonist treatment for luteinising hormone (LH) pulsatility analysis with kisspeptin-10 (0.3 µg/kg i.v. bolus) administered at 6 h on both days. Hot flash frequency and severity were self-reported for 7 days before and during NK3R antagonist administration. RESULTS LH fell from 29.3 ± 4.1 to 24.4 ± 3.8 IU/L (p < 0.05) after 7 days of NK3R antagonist treatment, with no change in follicle-stimulating hormone (FSH). Basal (non-pulsatile) LH secretion was reduced (549.0 ± 70.8 vs. 366.1 ± 92.1 IU/L/6 h, p = 0.006), and while the LH pulse frequency did not change in the group as a whole (from 0.8 ± 0.1 to 0.7 ± 0.1 pulses/h, ns), it did fall in the 8 women with hot flashes (from 1.0 ± 0.1 to 0.7 ± 0.1 pulses/h, p < 0.05). These women also reported a reduction in hot flash frequency (from 3.4 ± 1.2 to 1.0 ± 0.6 hot flashes/day, p = 0.008) whilst taking the NK3R antagonist. Kisspeptin-10 did not affect LH secretion with or without the NK3R antagonist. CONCLUSIONS The administration of an NK3R antagonist indicates a role for NKB in the regulation of LH/GnRH in postmenopausal women, whereas the lack of response to kisspeptin may reflect the hypo-oestrogenic state. These data support a link of LH/GnRH pulsatility and vasomotor symptoms with NK3R antagonism as a potential therapeutic approach.
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Anderson RC, Newton CL, Millar RP. Small Molecule Follicle-Stimulating Hormone Receptor Agonists and Antagonists. Front Endocrinol (Lausanne) 2018; 9:757. [PMID: 30728807 PMCID: PMC6352558 DOI: 10.3389/fendo.2018.00757] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 11/29/2018] [Indexed: 12/19/2022] Open
Abstract
The follicle-stimulating hormone receptor (FSHR) has been targeted therapeutically for decades, due to its pivotal role in reproduction. To date, only purified and recombinant/biosimilar FSH have been used to target FSHR in assisted reproduction, with the exception of corifollitropin alfa; a modified gonadotropin in which the FSH beta subunit is joined to the C-terminal peptide of the human choriogonadotropin beta subunit, to extend serum half-life. Assisted reproduction protocols usually entail the trauma of multiple injections of FSH to initiate and promote folliculogenesis, which has prompted the development of a number of orally-available low molecular weight (LMW) chemical scaffolds targeting the FSHR. Furthermore, the recently documented roles of the FSHR in diverse extragonadal tissues, including cancer, fat metabolism, and bone density regulation, has highlighted the potential utility of LMW modulators of FSHR activity. Despite these chemical scaffolds encompassing a spectrum of in vitro and in vivo activities and pharmacological profiles, none have yet reached the clinic. In this review we discuss the major chemical classes of LMW molecules targeting the FSHR, and document their activity profiles and current status of development, in addition to discussing potential clinical applications.
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Affiliation(s)
- Ross C. Anderson
- Centre for Neuroendocrinology, Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- *Correspondence: Ross C. Anderson
| | - Claire L. Newton
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Robert P. Millar
- Centre for Neuroendocrinology, Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
- Institute of Infectious Disease and Molecular Medicine, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Skorupskaite K, George JT, Veldhuis JD, Millar RP, Anderson RA. Neurokinin 3 receptor antagonism decreases gonadotropin and testosterone secretion in healthy men. Clin Endocrinol (Oxf) 2017; 87:748-756. [PMID: 28802064 DOI: 10.1111/cen.13445] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 08/01/2017] [Accepted: 08/08/2017] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Patients with mutations of neurokinin B (NKB) and its receptor show hypogonadotrophic hypogonadism, but there is little evidence for the importance of this pathway in reproductive function in normal men, or its functional hierarchy with kisspeptin. DESIGN An open label study wherein men (n = 6) were administered the NK3R antagonist MLE4901 40 mg orally twice a day for 7 days. Kisspeptin-10 (0.3 μg/kg iv bolus) was given before and on day 7 of NK3R antagonist treatment. PATIENTS Subjects were healthy men. MEASUREMENTS Reproductive hormones were measured before and during the NK3R antagonist administration, including frequent sampling on two occasions for analysis of pulsatile LH secretion. RESULTS LH, FSH and testosterone secretion were decreased during NK3R antagonist administration. LH showed a biphasic response, being reduced after 24 hours of treatment (4.5 ± 0.6 IU/L pretreatment to 1.7 ± 0.2 IU/L, P < .05), with partial recovery thereafter, but it was again decreased on day 7 (2.5 ± 0.6 IU/L, P < .05 vs pretreatment). FSH secretion was also suppressed, with a similar temporal pattern to that of LH. Testosterone secretion was decreased from 24 hours (18.4 ± 1.6 pretreatment vs 5.6 ± 1.5 nmol/L, P < .01) and remained suppressed throughout the treatment period. Analysis of LH pulsatility showed that both basal and pulsatile LH secretion were markedly suppressed but there was no detected change in LH pulse frequency. Kisspeptin-10 stimulated LH secretion, with similar responses before and during NK3R antagonist administration. CONCLUSIONS These data demonstrate a central role for NKB/NK3R in the physiological regulation of reproductive function in men, and that this is functionally upstream of kisspeptin-mediated GnRH secretion.
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Affiliation(s)
- Karolina Skorupskaite
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Jyothis T George
- Warwick Medical School, Coventry, UK
- Boehringer Ingelheim, Bracknell, UK
| | - Johannes D Veldhuis
- Endocrine Research Unit, Center for Translational Science Activities, Mayo Clinic, Rochester, MN, USA
| | - Robert P Millar
- Centre for Neuroendocrinology and Mammal Research Institute, University of Pretoria, Pretoria, South Africa
- Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Richard A Anderson
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
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Fabre-Nys C, Cognié J, Dufourny L, Ghenim M, Martinet S, Lasserre O, Lomet D, Millar RP, Ohkura S, Suetomi Y. The Two Populations of Kisspeptin Neurons Are Involved in the Ram-Induced LH Pulsatile Secretion and LH Surge in Anestrous Ewes. Endocrinology 2017; 158:3914-3928. [PMID: 28938486 DOI: 10.1210/en.2017-00429] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/29/2017] [Indexed: 12/22/2022]
Abstract
Exposure to a ram during spring stimulates luteinizing hormone (LH) secretion and can induce ovulation in sexually quiescent ewes ("ram effect"). Kisspeptin (Kiss) present in the arcuate nucleus (ARC) and the preoptic area (POA) is a potent stimulators of LH secretion. Our aim was to investigate whether Kiss neurons mediate the increase in LH secretion during the ram effect. With double immunofluorescent detection, we identified Kiss neurons (Kiss IR) activated (Fos IR) by exposure to a ram for 2 hours (M2) or 12 hours (M12) or to ewes for 2 hours (C). The density of cells Kiss + Fos IR and the proportion of Kiss IR cells that were also Fos IR cells were higher in M2 and M12 than in C in ARC (P < 0.002) and POA (P < 0.02). In ARC, these parameters were also higher in M12 than in M2 (P < 0.02 and P < 0.05). Kiss antagonist (P234 10-6M) administered by retrodialysis in POA for 3 hours at the time of introduction of the ram reduced the amplitude of the male-induced increase in LH concentration compared with solvent (P < 0.02). In ARC, P234 had a more limited effect (P < 0.038 1 hour after P234) but pulse frequency increased less than after solvent (P = 0.07). In contrast, Kiss antagonist (P271 10-4M) infused in ARC but not POA 6 to 18 hours after introduction of the ram prevented the LH surge in the ewe (0/6 vs 4/5 and 4/6 in C). These results suggest that both populations of Kiss neurons are involved in the ram-induced pulsatile LH secretion and in the LH surge.
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Affiliation(s)
- Claude Fabre-Nys
- Unité Mixte de Recherche 7247 Physiologie de la Reproduction et des Comportements, Centre National de la Recherche Scientifique, Institut National de Recherche Agronomique (INRA), University of Tours, Institut Français du Cheval et de l'Equitation, Institut Fédératif de Recherche 135, 37380 Nouzilly, France
| | - Juliette Cognié
- Unité Mixte de Recherche 7247 Physiologie de la Reproduction et des Comportements, Centre National de la Recherche Scientifique, Institut National de Recherche Agronomique (INRA), University of Tours, Institut Français du Cheval et de l'Equitation, Institut Fédératif de Recherche 135, 37380 Nouzilly, France
| | - Laurence Dufourny
- Unité Mixte de Recherche 7247 Physiologie de la Reproduction et des Comportements, Centre National de la Recherche Scientifique, Institut National de Recherche Agronomique (INRA), University of Tours, Institut Français du Cheval et de l'Equitation, Institut Fédératif de Recherche 135, 37380 Nouzilly, France
| | - Meriem Ghenim
- Unité Mixte de Recherche 7247 Physiologie de la Reproduction et des Comportements, Centre National de la Recherche Scientifique, Institut National de Recherche Agronomique (INRA), University of Tours, Institut Français du Cheval et de l'Equitation, Institut Fédératif de Recherche 135, 37380 Nouzilly, France
| | - Stephanie Martinet
- Unité Mixte de Recherche 7247 Physiologie de la Reproduction et des Comportements, Centre National de la Recherche Scientifique, Institut National de Recherche Agronomique (INRA), University of Tours, Institut Français du Cheval et de l'Equitation, Institut Fédératif de Recherche 135, 37380 Nouzilly, France
| | - Olivier Lasserre
- INRA Unité Expérimentale de Physiologie Animale de l'Orfrasière, 37380 Nouzilly, France
| | - Didier Lomet
- Unité Mixte de Recherche 7247 Physiologie de la Reproduction et des Comportements, Centre National de la Recherche Scientifique, Institut National de Recherche Agronomique (INRA), University of Tours, Institut Français du Cheval et de l'Equitation, Institut Fédératif de Recherche 135, 37380 Nouzilly, France
| | - Robert P Millar
- Centre for Neuroendocrinology, Department of Physiology, University of Pretoria, Pretoria 0084, South Africa
- Mammal Research Institute, Department of Zoology and Entomology, Institute of Infectious Diseases, University of Cape Town, Cape Town 7925, South Africa
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Millar RP, Sonigo C, Anderson RA, George J, Maione L, Brailly-Tabard S, Chanson P, Binart N, Young J. Hypothalamic-Pituitary-Ovarian Axis Reactivation by Kisspeptin-10 in Hyperprolactinemic Women With Chronic Amenorrhea. J Endocr Soc 2017; 1:1362-1371. [PMID: 29264460 PMCID: PMC5686678 DOI: 10.1210/js.2017-00328] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/11/2017] [Indexed: 11/23/2022] Open
Abstract
Context: Hyperprolactinemia-induced hypogonadotropic amenorrhea (hPRL-HA) is a major cause of hypothalamic gonadotrophin-releasing hormone (GnRH) deficiency in women. In hyperprolactinemic mice, we previously demonstrated that hypothalamic kisspeptin (Kp) expression was diminished and that Kp administration restored hypothalamic GnRH release, gonadotropin secretion, and ovarian cyclicity, suggesting that Kp neurons could also play a role in hPRL-HA. Objective: To study the effect of Kp-10 on the gonadotropic-ovarian axis in women with hPRL-HA. Patients: Two women (32 and 36 years old) with chronic hPRL-HA (prolactin: between 94 and 102 and 98 and 112 ng/mL, respectively) caused by cabergoline-resistant microprolactinomas. Interventions: Cabergoline was discontinued 6 months before inclusion. Blood samples were taken every 10 minutes for 12 hours during 2 consecutive days to evaluate luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion. Serum estradiol (E2), testosterone (T), and inhibin B (IB) levels were also measured. Vehicle or Kp-10 (1.5 μg/kg/h) was infused intravenously for 12 hours. Results: Kp-10 induced a significant increase in LH and FSH levels and increased LH pulses. E2, T, and IB serum levels were also significantly increased. Conclusions: In this exploratory study, we demonstrated that administration of Kp-10 reactivated gonadotropin secretion in women with hPRL-HA and increased ovarian activity. Our data suggest that, as in rodents, GnRH deficiency in hPRL-HA is also mediated by an impairment of hypothalamic Kp secretion. Kp-10 or its analogues could have therapeutic application as an alternative approach to restore ovarian function and fertility in women with hPRL-HA resistant to dopamine agonists and in whom pituitary surgery is not possible.
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Affiliation(s)
- Robert P Millar
- Centre for Neuroendocrinology, Departments of Immunology and Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria 0084, South Africa.,Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Charlotte Sonigo
- INSERM U1185, Paris Sud Medical School, Le Kremlin-Bicêtre, F-94276, France.,Reproductive Endocrinology Department, Le Kremlin-Bicêtre, F-94275, France
| | - Richard A Anderson
- MRC Centre for Reproductive Health, Queens Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Jyothis George
- MRC Centre for Reproductive Health, Queens Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Luigi Maione
- Reproductive Endocrinology Department, Le Kremlin-Bicêtre, F-94275, France.,Assistance Publique Hôpitaux de Paris (AP-HP), Bicêtre Hospital, Hormonology and Genetic Department, Le Kremlin-Bicêtre, F-94275, France
| | - Sylvie Brailly-Tabard
- Reproductive Endocrinology Department, Le Kremlin-Bicêtre, F-94275, France.,Assistance Publique Hôpitaux de Paris (AP-HP), Bicêtre Hospital, Hormonology and Genetic Department, Le Kremlin-Bicêtre, F-94275, France
| | - Philippe Chanson
- Reproductive Endocrinology Department, Le Kremlin-Bicêtre, F-94275, France.,Université Paris Sud, Paris-Sud Medical School, Le Kremlin-Bicêtre, F-94276, France
| | - Nadine Binart
- Reproductive Endocrinology Department, Le Kremlin-Bicêtre, F-94275, France
| | - Jacques Young
- Reproductive Endocrinology Department, Le Kremlin-Bicêtre, F-94275, France.,Université Paris Sud, Paris-Sud Medical School, Le Kremlin-Bicêtre, F-94276, France
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George JT, Hendrikse M, Veldhuis JD, Clarke IJ, Anderson RA, Millar RP. Effect of gonadotropin-inhibitory hormone on luteinizing hormone secretion in humans. Clin Endocrinol (Oxf) 2017; 86:731-738. [PMID: 28186349 DOI: 10.1111/cen.13308] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 01/09/2017] [Accepted: 02/03/2017] [Indexed: 01/01/2023]
Abstract
BACKGROUND Gonadotropin-inhibitory hormone (GnIH, human homologue of RFRP-3) suppresses gonadotropin secretion in animal models, but its effects have not been studied in the human. OBJECTIVE We tested the hypotheses that exogenous GnIH inhibits LH secretion (i) in postmenopausal women and (ii) in men concurrently administered exogenous kisspeptin. DESIGN Following in vitro and in vivo preclinical studies to functionally characterize the GnIH peptide, a dose-finding study (human GnIH: 1·5-150 μg/kg/h, iv for 3 h) was undertaken, and 50 μg/kg/h selected for further evaluation. Five postmenopausal women were administered 50 μg/kg/h iv infusion for 3 h or vehicle on two separate days. Four men were administered kisspeptin-10 (0·3 μg/kg iv bolus) with simultaneous infusion of GnIH (50 μg/kg/h, iv for 3 h) or vehicle. PARTICIPANTS Healthy postmenopausal women (mean age 58 ± 2 years, LH: 30·8 ± 2·9 IU/l, FSH: 78·7 ± 6·4 IU/l, oestradiol: <50 pmol/l) and men (39·8 ± 2·1 years, mean total testosterone 12·1 ± 1·8 nmol/l, LH 2·2 ± 0·2 IU/l). PRIMARY OUTCOME Change in area under curve (AUC) of LH during GnIHvs vehicle. RESULTS During GnIH administration in postmenopausal women, LH secretion decreased (ΔAUC: -9·9 ± 1·8 IU/3 h) vs vehicle (ΔAUC: -0·5 ± 1·7 IU/3 h; P = 0·02). Kisspeptin-10-stimulated LH responses in men were not affected by GnIH co-administration (60-min AUC of LH 6·2 ± 0·8 IU/h with kisspeptin-10 alone, 6·3 ± 1·0 IU/h, kisspeptin-10 with GnIH, P = 0·72). Exogenous GnIH was well tolerated, with no adverse events reported. CONCLUSIONS Gonadotropin-inhibitory hormone decreased LH secretion in postmenopausal women in this first-in-human study. Kisspeptin-stimulated LH secretion in men was not inhibited during concomitant administration of GnIH.
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Affiliation(s)
- J T George
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
- Diabetes Trials Unit, Endocrinology and Metabolism, Oxford Centre for Diabetes, Oxford, UK
| | - M Hendrikse
- Department of Medical Biochemistry and Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Observatory, South Africa
| | - J D Veldhuis
- Endocrine Research Unit, Center for Translational Science Activities, Mayo Clinic, Rochester, MN, USA
| | - I J Clarke
- Department of Physiology, School of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
| | - R A Anderson
- MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - R P Millar
- Department of Medical Biochemistry and Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Observatory, South Africa
- Mammal Research Institute and Centre for Neuroendocrinology, University of Pretoria, Pretoria, South Africa
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Skorupskaite K, George JT, Veldhuis JD, Millar RP, Anderson RA. Interactions Between Neurokinin B and Kisspeptin in Mediating Estrogen Feedback in Healthy Women. J Clin Endocrinol Metab 2016; 101:4628-4636. [PMID: 27636018 PMCID: PMC5155690 DOI: 10.1210/jc.2016-2132] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Kisspeptin and neurokinin B (NKB) are obligate for normal gonadotropin secretion, but their hierarchy is unexplored in normal women. OBJECTIVE To investigate the interaction between kisspeptin and NKB on estrogen-regulated LH secretion. DESIGN Women were treated with neurokinin-3 receptor (NK3R) antagonist followed by transdermal estradiol to induce LH secretion 48 hours later, with kisspeptin-10 or vehicle infusion during estrogen administration in a 2-way crossover study. SETTING Clinical research facility. PATIENTS OR OTHER PARTICIPANTS Healthy females with regular menses. INTERVENTION(S) NK3R antagonist AZD4901 40 mg twice daily orally was taken from cycle day 4-6 for 6 days (n = 10, with 10 no treatment controls). Transdermal estradiol patches (200 μg/d) were applied after 5 days of NK3R antagonist treatment. At 24-hour estradiol treatment, women were randomized to 7-hour kisspeptin-10 (4 μg/kg/h) or vehicle iv infusion, with the alternate infusion in a subsequent cycle. MAIN OUTCOME MEASURE(S) Plasma gonadotropin and estradiol secretion. RESULTS After an initial suppression, LH secretion was increased 48 hours after estradiol treatment. Kisspeptin-10 increased LH secretion during the inhibitory phase, and LH remained elevated beyond the discontinuation of kisspeptin-10 infusion. NK3R antagonist decreased LH pulse frequency (0.5 ± 0.2 vs 0.7 ± 0.2 pulses/h, P < .05) and stimulated FSH response to kisspeptin-10 infusion (10.7 ± 11.0 vs 5.0 ± 3.6 IU/L, P < .05) with a nonsignificant rise in LH. The duration of LH response was blunted, with LH being lower at 48 hours (7.5 ± 4.8 vs 15.0 ± 11.4 IU/L, P < .05). CONCLUSIONS These data demonstrate that NKB signaling regulates GnRH/LH secretion in normal women, and is predominantly proximal to kisspeptin in mediating estrogenic positive and negative feedback on LH secretion.
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Affiliation(s)
- Karolina Skorupskaite
- MRC Centre for Reproductive Health (K.S., J.T.G., R.A.A.), The Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom; Endocrine Research Unit (J.D.V.), Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905; and Mammal Research Unit and Centre for Neuroendocrinology (R.P.M.), University of Pretoria, 0028 Pretoria, South Africa and MRC Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7925 Observatory, South Africa
| | - Jyothis T George
- MRC Centre for Reproductive Health (K.S., J.T.G., R.A.A.), The Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom; Endocrine Research Unit (J.D.V.), Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905; and Mammal Research Unit and Centre for Neuroendocrinology (R.P.M.), University of Pretoria, 0028 Pretoria, South Africa and MRC Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7925 Observatory, South Africa
| | - Johannes D Veldhuis
- MRC Centre for Reproductive Health (K.S., J.T.G., R.A.A.), The Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom; Endocrine Research Unit (J.D.V.), Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905; and Mammal Research Unit and Centre for Neuroendocrinology (R.P.M.), University of Pretoria, 0028 Pretoria, South Africa and MRC Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7925 Observatory, South Africa
| | - Robert P Millar
- MRC Centre for Reproductive Health (K.S., J.T.G., R.A.A.), The Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom; Endocrine Research Unit (J.D.V.), Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905; and Mammal Research Unit and Centre for Neuroendocrinology (R.P.M.), University of Pretoria, 0028 Pretoria, South Africa and MRC Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7925 Observatory, South Africa
| | - Richard A Anderson
- MRC Centre for Reproductive Health (K.S., J.T.G., R.A.A.), The Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom; Endocrine Research Unit (J.D.V.), Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905; and Mammal Research Unit and Centre for Neuroendocrinology (R.P.M.), University of Pretoria, 0028 Pretoria, South Africa and MRC Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7925 Observatory, South Africa
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Barranco JAJ, Millar RP, Fuentes F, Bover E, Pimentel E, Basulto R, Calzada L, Morán R, Rodríguez A, Garay H, Reyes O, Castro MD, Bringas R, Arteaga N, Toudurí H, Rabassa M, Fernández Y, Serradelo A, Hernández E, Guillén GE. Gradual reduction of testosterone using a gonadotropin-releasing hormone vaccination delays castration resistance in a prostate cancer model. Oncol Lett 2016; 12:963-970. [PMID: 27446378 DOI: 10.3892/ol.2016.4679] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 12/16/2015] [Indexed: 01/21/2023] Open
Abstract
In a previous study aimed to design a novel prostate cancer vaccine, the authors of the present study demonstrated the advantage of combining the adjuvants Montanide ISA 51 with very small size proteoliposomes (VSSP) to promote a significant humoral immune response to gonadotropin-releasing hormone (GnRH) in healthy animals. The present study compared the efficacy of this vaccine formulation versus the standard treatment currently available in terms of preventing the development of tumors in DD/S mice injected with Shionogi carcinoma (SC) 115 cells. The results demonstrated that 5 non-vaccinated control mice exhibited a fast tumor growth, and succumbed to the disease within 19-31 days. Mice immunized with the GnRH/Montanide ISA 51/VSSP vaccine exhibited a moderate decline in testosterone levels that was associated with a decrease in anti-GnRH antibody titers, which lead to a sustained tumor growth inhibition. In total, 2 mice in the immunized group exhibited complete remission of the tumor for the duration of the present study. In addition, castrated mice, which were used as a control for standard hormonal therapy, exhibited an accelerated decrease in tumor size. However, tumor relapse was observed between days 50 and 54, and between days 65 and 85, following the injection of SC 155 cells. Therefore, these mice were sacrificed at day 90. The present study concludes that the slow and moderate reduction of testosterone levels observed using the GnRH-based vaccine may delay the appearance of castration resistance in a Shionogi prostate cancer model. These findings suggest that this vaccine may be used to delay castration resistance in patients with prostate cancer.
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Affiliation(s)
- Jesús A Junco Barranco
- Department of Vaccines, Center for Genetic Engineering and Biotechnology, Camagüey, Camagüey 70100, Cuba
| | - Robert P Millar
- Mammal Research Institute and Centre for Neuroendocrinology, University of Pretoria, Pretoria, Gauteng 0028, South Africa; MRC Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, Western Cape 7925, South Africa
| | - Franklin Fuentes
- Department of Vaccines, Center for Genetic Engineering and Biotechnology, Camagüey, Camagüey 70100, Cuba
| | - Eddy Bover
- Department of Vaccines, Center for Genetic Engineering and Biotechnology, Camagüey, Camagüey 70100, Cuba
| | - Eulogio Pimentel
- Center for Genetic Engineering and Biotechnology, Havana, Havana 10600, Cuba
| | - Roberto Basulto
- Department of Vaccines, Center for Genetic Engineering and Biotechnology, Camagüey, Camagüey 70100, Cuba
| | - Lesvia Calzada
- Department of Vaccines, Center for Genetic Engineering and Biotechnology, Camagüey, Camagüey 70100, Cuba
| | - Rolando Morán
- Department of Vaccines, Center for Genetic Engineering and Biotechnology, Camagüey, Camagüey 70100, Cuba
| | - Ayni Rodríguez
- Medical University of Camagüey, Camagüey, Camagüey 70100, Cuba
| | - Hilda Garay
- Center for Genetic Engineering and Biotechnology, Havana, Havana 10600, Cuba
| | - Osvaldo Reyes
- Center for Genetic Engineering and Biotechnology, Havana, Havana 10600, Cuba
| | - Maria D Castro
- Department of Vaccines, Center for Genetic Engineering and Biotechnology, Camagüey, Camagüey 70100, Cuba
| | - Ricardo Bringas
- Center for Genetic Engineering and Biotechnology, Havana, Havana 10600, Cuba
| | - Niurka Arteaga
- Department of Vaccines, Center for Genetic Engineering and Biotechnology, Camagüey, Camagüey 70100, Cuba
| | - Henio Toudurí
- Medical University of Camagüey, Camagüey, Camagüey 70100, Cuba
| | - Mauricio Rabassa
- Department of Vaccines, Center for Genetic Engineering and Biotechnology, Camagüey, Camagüey 70100, Cuba
| | | | - Andrés Serradelo
- Department of Vaccines, Center for Genetic Engineering and Biotechnology, Camagüey, Camagüey 70100, Cuba
| | - Eduardo Hernández
- Department of Vaccines, Center for Genetic Engineering and Biotechnology, Camagüey, Camagüey 70100, Cuba
| | - Gerardo E Guillén
- Center for Genetic Engineering and Biotechnology, Havana, Havana 10600, Cuba
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Pineda R, Plaisier F, Millar RP, Ludwig M. Amygdala Kisspeptin Neurons: Putative Mediators of Olfactory Control of the Gonadotropic Axis. Neuroendocrinology 2016; 104:223-238. [PMID: 27054958 DOI: 10.1159/000445895] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 04/04/2016] [Indexed: 11/19/2022]
Abstract
Kisspeptins and their receptors are potent regulators of the gonadotropic axis. Kisspeptin neurons are found mainly in the hypothalamic arcuate nucleus and the anteroventral periventricular nucleus. However, there is also a third population of kisspeptin neurons, located in the amygdala. We used fluorescence immunohistochemistry to quantify and localize the amygdala kisspeptin neurons and to reveal close apposition and putative innervations by vasopressinergic and tyrosine hydroxylase-positive dopaminergic neurons. Using microinjections of retro- and anterograde tracers, and viral transfection systems in rats and transgenic mice, we showed reciprocal connectivity between the accessory olfactory bulb and the amygdala kisspeptin neurons. In vitro recordings indicate an inhibitory action of kisspeptin on mitral cells in the accessory olfactory bulb. Using viral specific-cell gene expression in transgenic mice in combination with double immunofluorescence histochemistry, we found that the amygdala kisspeptin neurons also project to gonadotropin-releasing hormone (GnRH) neurons in the preoptic area. Our neuroanatomical and electrophysiological data suggest that amygdala kisspeptin neurons integrate social behaviour and odour information into GnRH neurons in the preoptic area to coordinate the gonadotropic axis and the appropriate output behaviour to odour cues.
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Affiliation(s)
- Rafael Pineda
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
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Pineda R, Sabatier N, Ludwig M, Millar RP, Leng G. A Direct Neurokinin B Projection from the Arcuate Nucleus Regulates Magnocellular Vasopressin Cells of the Supraoptic Nucleus. J Neuroendocrinol 2016; 28. [PMID: 26610724 DOI: 10.1111/jne.12342] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 11/02/2015] [Accepted: 11/22/2015] [Indexed: 01/11/2023]
Abstract
Central administration of neurokinin B (NKB) agonists stimulates immediate early gene expression in the hypothalamus and increases the secretion of vasopressin from the posterior pituitary through a mechanism that depends on the activation of neurokinin receptor 3 receptors (NK3R). The present study reports that, in the rat, immunoreactivity for NK3R is expressed in magnocellular vasopressin and oxytocin neurones in the supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus, and that NKB immunoreactivity is expressed in fibres in close juxtaposition with vasopressin neurones at both of these sites. Retrograde tracing in the rat shows that some NKB-expressing neurones in the arcuate nucleus project to the SON and, in mice, using an anterograde tracing approach, it is found that kisspeptin-expressing neurones of the arcuate nucleus, which are known to co-express NKB, project to the SON and PVN. Finally, i.c.v. injection of the NK3R agonist senktide is shown to potently increase the electrical activity of vasopressin neurones in the SON in vivo with no significant effect detected on oxytocin neurones. The results suggest that NKB-containing neurones in the arcuate nucleus regulate the secretion of vasopressin from magnocellular neurones in rodents, and the possible significance of this is discussed.
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Affiliation(s)
- R Pineda
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | - N Sabatier
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | - M Ludwig
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | - R P Millar
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
- MRC Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - G Leng
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
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Newton CL, Anderson RC, Millar RP. Therapeutic Neuroendocrine Agonist and Antagonist Analogs of Hypothalamic Neuropeptides as Modulators of the Hypothalamic-Pituitary-Gonadal Axis. Endocr Dev 2016; 30:106-29. [PMID: 26684214 DOI: 10.1159/000439337] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
Reproductive hormones play a role at all stages of life and affect most tissues of the body. Gonadotropin-releasing hormone (GnRH) synthesized in the hypothalamus stimulates the secretion of gonadotropins which in turn stimulate gonadal sex hormone production and gamete formation. This hypothalamic-pituitary-gonadal (HPG) axis has, therefore, been the target for the development of numerous drugs which regulate it at various points. These include sex steroid agonists and antagonists, inhibitors of sex steroid biosynthesis, and GnRH agonists and antagonists, which have found extensive applications in treating numerous conditions such as precocious puberty, delayed puberty, prostate cancer, benign prostatic hyperplasia, endometriosis, uterine fibroids and also in in vitro fertilization protocols. The novel neuroendocrine peptides, kisspeptin (KP) and neurokinin B (NKB), were recently discovered as upstream regulators of GnRH, and inactivating mutations of KP and NKB ligands or receptors result in a failure to progress through puberty. Agonists and antagonists of KP and NKB are being developed as more subtle modulators of the HPG axis. These new drugs offer additional and alternative therapeutic options in pediatric and adult hormone-dependent diseases.
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Fraser GL, Hoveyda HR, Clarke IJ, Ramaswamy S, Plant TM, Rose C, Millar RP. The NK3 Receptor Antagonist ESN364 Interrupts Pulsatile LH Secretion and Moderates Levels of Ovarian Hormones Throughout the Menstrual Cycle. Endocrinology 2015; 156:4214-25. [PMID: 26305889 DOI: 10.1210/en.2015-1409] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Women's health disorders such as uterine fibroids and endometriosis are currently treated by GnRH modulators that effectively suppress the hypothalamic-pituitary-gonadal axis. The neurokinin-3 receptor (NK3R) is an alternative target with an important role in the modulation of this axis. In this report, we demonstrate that systemic administration of an NK3R antagonist (ESN364) prolongs the LH interpulse interval in ovarectomized ewes and significantly lowers plasma LH and FSH concentrations in castrated nonhuman primates (Macaca fascicularis). Moreover, daily oral dosing of ESN364 throughout the menstrual cycle in M fascicularis lowered plasma estradiol levels in a dose-dependent manner, although nadir levels of estradiol were maintained well above menopausal levels. Nevertheless, estradiol levels during the follicular phase were sufficiently inhibited at all doses to preclude the triggering of ovulation as evidenced by the absence of the LH surge and failure of a subsequent luteal phase rise in plasma progesterone concentrations, consistent with the absence of normal cycle changes in the uterus. Apart from the point at surge, FSH levels were not altered over the course of the menstrual cycle. These effects of ESN364 were reversible upon cessation of drug treatment. Together these data support the proposed role of neurokinin B-NK3R signaling in the control of pulsatile GnRH secretion. Furthermore, in contrast to GnRH antagonists, NK3R antagonists induce a partial suppression of estradiol and thereby offer a viable therapeutic approach to the treatment of ovarian sex hormone disorders with a mitigated risk of menopausal-like adverse events in response to long-term drug exposure.
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Affiliation(s)
- Graeme L Fraser
- Euroscreen SA (G.L.F., H.R.H.), 6041 Gosselies, Belgium; Department of Physiology (I.J.C.), Monash University, Clayton 3800, Victoria, Australia; Department of Obstetrics, Gynecology, and Reproductive Sciences (S.R., T.M.P.), University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213; Covance Laboratories GmbH (C.R.), 48163 Münster, Germany; Mammal Research Unit (R.P.M.), University of Pretoria and Medical Research Center Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7701 Cape Town, South Africa
| | - Hamid R Hoveyda
- Euroscreen SA (G.L.F., H.R.H.), 6041 Gosselies, Belgium; Department of Physiology (I.J.C.), Monash University, Clayton 3800, Victoria, Australia; Department of Obstetrics, Gynecology, and Reproductive Sciences (S.R., T.M.P.), University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213; Covance Laboratories GmbH (C.R.), 48163 Münster, Germany; Mammal Research Unit (R.P.M.), University of Pretoria and Medical Research Center Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7701 Cape Town, South Africa
| | - Iain J Clarke
- Euroscreen SA (G.L.F., H.R.H.), 6041 Gosselies, Belgium; Department of Physiology (I.J.C.), Monash University, Clayton 3800, Victoria, Australia; Department of Obstetrics, Gynecology, and Reproductive Sciences (S.R., T.M.P.), University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213; Covance Laboratories GmbH (C.R.), 48163 Münster, Germany; Mammal Research Unit (R.P.M.), University of Pretoria and Medical Research Center Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7701 Cape Town, South Africa
| | - Suresh Ramaswamy
- Euroscreen SA (G.L.F., H.R.H.), 6041 Gosselies, Belgium; Department of Physiology (I.J.C.), Monash University, Clayton 3800, Victoria, Australia; Department of Obstetrics, Gynecology, and Reproductive Sciences (S.R., T.M.P.), University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213; Covance Laboratories GmbH (C.R.), 48163 Münster, Germany; Mammal Research Unit (R.P.M.), University of Pretoria and Medical Research Center Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7701 Cape Town, South Africa
| | - Tony M Plant
- Euroscreen SA (G.L.F., H.R.H.), 6041 Gosselies, Belgium; Department of Physiology (I.J.C.), Monash University, Clayton 3800, Victoria, Australia; Department of Obstetrics, Gynecology, and Reproductive Sciences (S.R., T.M.P.), University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213; Covance Laboratories GmbH (C.R.), 48163 Münster, Germany; Mammal Research Unit (R.P.M.), University of Pretoria and Medical Research Center Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7701 Cape Town, South Africa
| | - Claudia Rose
- Euroscreen SA (G.L.F., H.R.H.), 6041 Gosselies, Belgium; Department of Physiology (I.J.C.), Monash University, Clayton 3800, Victoria, Australia; Department of Obstetrics, Gynecology, and Reproductive Sciences (S.R., T.M.P.), University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213; Covance Laboratories GmbH (C.R.), 48163 Münster, Germany; Mammal Research Unit (R.P.M.), University of Pretoria and Medical Research Center Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7701 Cape Town, South Africa
| | - Robert P Millar
- Euroscreen SA (G.L.F., H.R.H.), 6041 Gosselies, Belgium; Department of Physiology (I.J.C.), Monash University, Clayton 3800, Victoria, Australia; Department of Obstetrics, Gynecology, and Reproductive Sciences (S.R., T.M.P.), University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213; Covance Laboratories GmbH (C.R.), 48163 Münster, Germany; Mammal Research Unit (R.P.M.), University of Pretoria and Medical Research Center Receptor Biology Unit, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, 7701 Cape Town, South Africa
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Viljoen IM, van Helden PD, Millar RP. Mycobacterium bovis infection in the lion (Panthera leo): Current knowledge, conundrums and research challenges. Vet Microbiol 2015; 177:252-60. [PMID: 25891424 DOI: 10.1016/j.vetmic.2015.03.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 03/24/2015] [Accepted: 03/28/2015] [Indexed: 01/16/2023]
Abstract
Mycobacterium bovis has global public-health and socio-economic significance and can infect a wide range of species including the lion (Panthera leo) resulting in tuberculosis. Lions are classified as vulnerable under the IUCN Red List of Threatened Species and have experienced a 30% population decline in the past two decades. However, no attempt has been made to collate and critically evaluate the available knowledge of M. bovis infections in lions and potential effects on population. In this review we set out to redress this. Arguments suggesting that ingestion of infected prey animals are the main route of infection for lions have not been scientifically proven and research is needed into other possible sources and routes of infection. The paucity of knowledge on host susceptibility, transmission directions and therefore host status, manifestation of pathology, and epidemiology of the disease in lions also needs to be addressed. Advances have been made in diagnosing the presence of M. bovis in lions. However, these diagnostic tests are unable to differentiate between exposure, presence of infection, or stage of disease. Furthermore, there are contradictory reports on the effects of M. bovis on lion populations with more data needed on disease dynamics versus the lion population's reproductive dynamics. Knowledge on disease effects on the lion reproduction and how additional stressors such as drought or co-morbidities may interact with tuberculosis is also lacking. Filling these knowledge gaps will contribute to the understanding of mycobacterial infections and disease in captive and wild lions and assist in lion conservation endeavours.
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Affiliation(s)
- Ignatius M Viljoen
- SA MRC Centre for TB Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Francie van Zijl Drive, Tygerberg, 7505, South Africa; Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Lynwood Road, Pretoria, 0002, South Africa.
| | - Paul D van Helden
- SA MRC Centre for TB Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Francie van Zijl Drive, Tygerberg, 7505, South Africa
| | - Robert P Millar
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Lynwood Road, Pretoria, 0002, South Africa; MRC Receptor Biology Unit, IDM, University of Cape Town, Observatory, 7935, South Africa
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Mayevu NMI, Choe H, Abagyan R, Seong JY, Millar RP, Katz AA, Flanagan CA. Histidine(7.36(305)) in the conserved peptide receptor activation domain of the gonadotropin releasing hormone receptor couples peptide binding and receptor activation. Mol Cell Endocrinol 2015; 402:95-106. [PMID: 25583361 DOI: 10.1016/j.mce.2015.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 01/06/2015] [Accepted: 01/06/2015] [Indexed: 12/29/2022]
Abstract
Transmembrane helix seven residues of G protein-coupled receptors (GPCRs) couple agonist binding to a conserved receptor activation mechanism. Amino-terminal residues of the GnRH peptide determine agonist activity. We investigated GnRH interactions with the His(7.36(305)) residue of the GnRH receptor, using functional and computational analysis of modified GnRH receptors and peptides. Non-polar His(7.36(305)) substitutions decreased receptor affinity for GnRH four- to forty-fold, whereas GnRH signaling potency was more decreased (~150-fold). Uncharged polar His(7.36(305)) substitutions decreased GnRH potency, but not affinity. [2-Nal(3)]-GnRH retained high affinity at receptors with non-polar His(7.36(305)) substitutions, supporting a role for His(7.36(305)) in recognizing Trp(3) of GnRH. Compared with GnRH, [2-Nal(3)]-GnRH potency was lower at the wild type GnRH receptor, but unchanged or higher at mutant receptors. Results suggest that His(7.36(305)) of the GnRH receptor forms two distinct interactions that determine binding to Trp(3) and couple agonist binding to the conserved transmembrane domain network that activates GPCRs.
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Affiliation(s)
- Nkateko M I Mayevu
- Medical Research Council Receptor Biology Research Unit, Institute of Infectious Diseases and Molecular Medicine, Division of Medical Biochemistry, University of Cape Town Health Sciences Faculty, Observatory, Cape Town 7925, South Africa
| | - Han Choe
- Department of Physiology and Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Seoul 138-736, Korea
| | - Ruben Abagyan
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92039, USA
| | - Jae Young Seong
- Graduate School of Medicine, Korea University, Seoul 136-705, Korea
| | - Robert P Millar
- Medical Research Council Receptor Biology Research Unit, Institute of Infectious Diseases and Molecular Medicine, Division of Medical Biochemistry, University of Cape Town Health Sciences Faculty, Observatory, Cape Town 7925, South Africa; Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
| | - Arieh A Katz
- Medical Research Council Receptor Biology Research Unit, Institute of Infectious Diseases and Molecular Medicine, Division of Medical Biochemistry, University of Cape Town Health Sciences Faculty, Observatory, Cape Town 7925, South Africa
| | - Colleen A Flanagan
- Medical Research Council Receptor Biology Research Unit, Institute of Infectious Diseases and Molecular Medicine, Division of Medical Biochemistry, University of Cape Town Health Sciences Faculty, Observatory, Cape Town 7925, South Africa; School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Private bag 3, Wits 2050, South Africa.
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Affiliation(s)
- Robert P Millar
- Centre for Neuroendocrinology and Mammal Research Institute, University of Pretoria, Pretoria, South Africa
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Li Q, Millar RP, Clarke IJ, Smith JT. Evidence that Neurokinin B Controls Basal Gonadotropin-Releasing Hormone Secretion but Is Not Critical for Estrogen-Positive Feedback in Sheep. Neuroendocrinology 2015; 101:161-74. [PMID: 25677216 DOI: 10.1159/000377702] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 02/04/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND Loss-of-function mutations in genes encoding kisspeptin or neurokinin B (NKB) or their receptors cause infertility. NKB is coproduced in kisspeptin neurons in the arcuate nucleus (ARC), and these neurons also produce the NKB receptor (NK3R), allowing autosynaptic function. We tested the hypothesis that NKB action in ARC kisspeptin neurons is aligned with increased pulsatile secretion of luteinizing hormone (LH) and/or activation of the estrogen-induced LH surge in ewes. METHODS Using in situ hybridization and immunohistochemistry, we examined NKB expression in kisspeptin neurons during the ovine estrous cycle. We infused kisspeptin, senktide (an NK3R agonist), or dynorphin into the lateral ventricle during the luteal phase of the estrous cycle to determine effects on pulsatile LH secretion. Finally, we examined the effect of an NK3R antagonist (MRK-08) in ovariectomized ewes. RESULTS NKB (Tac3) mRNA expression in mid-ARC kisspeptin neurons was elevated during the mid-to-late follicular phase of the estrous cycle. The number of NKB-immunoreactive cells and NKB/kisspeptin terminals in the median eminence was similar during the estrous cycle. Kisspeptin and senktide increased LH pulse frequency and mean LH levels. Central MRK-08 infusion eliminated the LH pulses but did not prevent an estrogen-positive feedback on LH secretion. CONCLUSIONS NKB expression in ARC kisspeptin neurons is upregulated during the late follicular phase of the estrous cycle, when the pulsatile secretion of gonadotropin-releasing hormone (GnRH)/LH is maximal. When GnRH/LH secretion is minimal, central senktide infusion induces LH secretion, similar to the response to kisspeptin. Although the increase in LH in response to senktide appeared surge-like, we did not observe any change in the surge following NK3R antagonist treatment. We conclude that NKB plays a role in increasing basal GnRH/LH pulsatility in the follicular phase of the cycle but is not essential for estrogen-induced positive feedback.
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Affiliation(s)
- Qun Li
- Department of Physiology, Monash University, Clayton, Vic., Australia
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Abstract
Kisspeptin (KP) is now well recognized as a potent stimulator of gonadotropin-releasing hormone (GnRH) secretion and thereby a major regulator of the neuroendocrine-reproductive axis. KP signals via KISS1R, a G protein-coupled receptor (GPCR) that activates the G proteins Gαq/11. Modulation of the interaction of KP with KISS1R is therefore a potential new therapeutic target for stimulating (in infertility) or inhibiting (in hormone-dependent diseases) the reproductive hormone cascade. Major efforts are underway to target KISS1R in the treatment of sex steroid hormone-dependent disorders and to stimulate endogenous hormonal responses along the neuroendocrine axis as part of in vitro fertilization protocols. The development of analogs modulating KISS1R signaling will be aided by an understanding of the intracellular pathways and dynamics of KISS1R signaling under normal and pathological conditions. This review focuses on KISS1R recruitment of intracellular signaling (Gαq/11- and β-arrestin-dependent) pathways that mediate GnRH secretion and the respective roles of rapid desensitization, internalization, and recycling of resensitized receptors in maintaining an active population of KISS1R at the cell surface to facilitate prolonged KP signaling. Additionally, this review summarizes and discusses the major findings of an array of studies examining the desensitization of KP signaling in man, domestic and laboratory animals. This discussion highlights the major effects of ligand efficacy and concentration and the physiological, developmental, and metabolic status of the organism on KP signaling. Finally, the potential for the utilization of KP and analogs in stimulating and inhibiting the reproductive hormone cascade as an alternative to targeting the downstream GnRH receptor is discussed.
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Affiliation(s)
- Robert P Millar
- Mammal Research Institute, University of Pretoria, Pretoria, South Africa
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Affiliation(s)
- Robert P Millar
- Mammal Research Institute, University of Pretoria, Pretoria 0018, South Africa; and Medical Research Council Receptor Biology Unit, University of Cape Town, Cape Town 7539, South Africa
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Gore AC, Balthazart J, Bikle D, Carpenter DO, Crews D, Czernichow P, Diamanti-Kandarakis E, Dores RM, Grattan D, Hof PR, Hollenberg AN, Lange C, Lee AV, Levine JE, Millar RP, Nelson RJ, Porta M, Poth M, Power DM, Prins GS, Ridgway EC, Rissman EF, Romijn JA, Sawchenko PE, Sly PD, Söder O, Taylor HS, Tena-Sempere M, Vaudry H, Wallen K, Wang Z, Wartofsky L, Watson CS. Policy decisions on endocrine disruptors should be based on science across disciplines: a response to Dietrich et al. Horm Res Paediatr 2014; 80:305-8. [PMID: 24107550 DOI: 10.1159/000355668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- A C Gore
- Division of Pharmacology and Toxicology, The University of Texas, Austin, Tex., USA
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Abstract
Acute systemic stress disrupts reproductive function by inhibiting pulsatile gonadotropin secretion. The underlying mechanism involves stress-induced suppression of the GnRH pulse generator, the functional unit of which is considered to be the hypothalamic arcuate nucleus kisspeptin/neurokinin B/dynorphin A neurons. Agonists of the neurokinin B (NKB) receptor (NK3R) have been shown to suppress the GnRH pulse generator, in a dynorphin A (Dyn)-dependent fashion, under hypoestrogenic conditions, and Dyn has been well documented to mediate several stress-related central regulatory functions. We hypothesized that the NKB/Dyn signaling cascade is required for stress-induced suppression of the GnRH pulse generator. To investigate this ovariectomized rats, iv administered with Escherichia coli lipopolysaccharide (LPS) following intracerebroventricular pretreatment with NK3R or κ-opioid receptor (Dyn receptor) antagonists, were subjected to frequent blood sampling for hormone analysis. Antagonism of NK3R, but not κ-opioid receptor, blocked the suppressive effect of LPS challenge on LH pulse frequency. Neither antagonist affected LPS-induced corticosterone secretion. Hypothalamic arcuate nucleus NKB neurons project to the paraventricular nucleus, the major hypothalamic source of the stress-related neuropeptides CRH and arginine vasopressin (AVP), which have been implicated in the stress-induced suppression of the hypothalamic-pituitary-gonadal axis. A separate group of ovariectomized rats was, therefore, used to address the potential involvement of central CRH and/or AVP signaling in the suppression of LH pulsatility induced by intracerebroventricular administration of a selective NK3R agonist, senktide. Neither AVP nor CRH receptor antagonists affected the senktide-induced suppression of the LH pulse; however, antagonism of type 2 CRH receptors attenuated the accompanying elevation of corticosterone levels. These data indicate that the suppression of the GnRH pulse generator by acute systemic stress requires hypothalamic NKB/NK3R signaling and that any involvement of CRH therewith is functionally upstream of NKB.
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Affiliation(s)
- P Grachev
- Division of Women's Health (P.G., X.F.L., M.H.H., S.Y.L., K.T.O.), School of Medicine, King's College London, United Kingdom; Mammal Research Institute (R.P.M.), University of Pretoria, Pretoria, South Africa; Medical Research Council Receptor Biology Unit, University of Cape Town, Cape Town, South Africa; Centre for Integrative Physiology, University of Edinburgh, Scotland; and Henry Wellcome Laboratory for Integrative Neuroscience & Endocrinology (S.L.L.), University of Bristol, Bristol, United Kingdom
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Anderson RC, Newton CL, Millar RP, Katz AA. The Brugia malayi neuropeptide receptor-4 is activated by FMRFamide-like peptides and signals via Gαi. Mol Biochem Parasitol 2014; 195:54-8. [DOI: 10.1016/j.molbiopara.2014.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/04/2014] [Accepted: 07/07/2014] [Indexed: 01/25/2023]
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